Snowman boiler help

I have a very old McCoy & Otte steam boiler Snowman. The house is an 1865 Victorian. It has a 30' single wall pipe with two right angles before reaching the chimney in the center of the house, running through the laundry room and kitchen.
Undoubtedly both the boiler and pipe are insulated with asbestos, which will require professional remediation. I know the boiler (cast iron, made in Peekskill, NY in 1905) is still in remarkably good shape, efficiency has always tested in the upper mid 80's. The flue pipe currently adds a lot of heat to the kitchen and pantry, but if I were to replace it with a new double wall, insulated pipe it would undoubtedly no longer be putting much heat into those rooms.
I am considering removing the flue pipe and re-insulating the boiler after asbestos removal, installing a new burner (raising it up to the old coal feed door, as shown above), adding a radiator to the kitchen, and putting a power vent on the old boiler. The cast iron on this old boiler is in remarkably condition and with proper maintenance for last another hundred years. We also have a welder in the family who could nickel weld any leaks that might develop (provided we can get to them).

All the current radiators in the house are heating nicely after adding more five more main vents in various places on the header and getting the right vents on each radiator. I'm open to suggestions (yeah, even replacing the boiler with something newer that can be safely power vented).

I'd especially be interested in reading what @EdTheHeaterMan thinks about this plan.

Thanks in advance from a newbie here.

Agreed.

One of my Dead Men's Books says this type of boiler is something like 40% efficient on gas or oil. Much of the heat goes up the chimney, which is why the smoke pipe does a good job of heating the kitchen and pantry. It is possible to add baffles to this type of boiler, so the hot flue gases give off more of their heat to the iron, but on this type of boiler that's just a band-aid.

Where are you located?

There are 2 ways to go here. One is much less expensive than the other. The asbestos insulation seems to be encapsulated so the health issue is minimal. What condition is the rest of the pipe insulation? An abatement contractor can remove all the asbestos then you need to add insulation back to the boiler and pipes, or you can have any problem areas encapsulated (if any) for much less. There are many public buildings that have encapsulated asbestos in the building and the health departments give the building an approval as long as the abatement contractor certifies that the asbestos is encapsulated properly. Cost is always a factor in asbestos abatement and as long as it is deemed "safe" I have no problem leaving it there.

Since the boiler doors need to be opened for annual maintenance, the asbestos near the doors must be properly sealed with a fireproof material that will encapsulate the asbestos. I find that the USG Structo-lite is a great product for that purpose. Get a 50 lb. bag and a plastic container to store it.  You might use a 12 ounces per year to reseal the boiler cleanout door and vent connector to the chimney base. That should be enough to last you 75 years.  

The idea of installing a burner in the fire door will end up being much less expensive than a replacement MegaSteam. The savings will be very cost effective, however there is always a gamble with that project on a boiler that old. I doubt you will find a professional that will do the job, for 2 reasons, the age of the boiler and most of the techs that know how to do the job are dead.      So that turns this into a DIY job for the owner of that boiler.   With that in mind, the DIY installer will need the services of a professional oil burner technician to commission the job once the new (or high efficiency gently used) oil burner is ready to fire.  I will not recommend this project to someone that is just going to keep their fingers crossed that the oil burner they select is a plug and play component.  

So option one will be a DIY that may cost as little as $500.00 or as much as $9000.00 depending on who does the job.  Either way, that price will be a fraction of the price of a complete replacement steamer.   I’m partial to the Velocity Boiler Works (version of the MegaSteam) Freeport-2 

The other option would be a replacement steam boiler with all the asbestos abatement work that goes along with that job.  Since we don't quote prices here let’s just say that it will be in the 5 figure range and the first number will not be a one (1)  This additional cost will increase your savings by about 5% over the savings that the DIY fire door burner job would yield.  Ask me how I know?

With the chimney 30 ft away, I don't believe the MegaSteam would draft. 3 pass boilers do not like long horizontal runs.

I don't usually push gas conversions, but a gas fired power vent with sidewall termination could be an option. A complete, correctly piped steam system, along with addressing the asbestos is major $$$. But its time.

The boiler is in a pit? Looks like a high water line.

To be perfectly honest you have two options. If the boiler is working properly and you are satisfied with the monthly operating cost, let sleeping dogs lay. These old boilers were built to last the life of the building. It appears this unit has been maintained over its lifespan so why go messing with stuff at this point? Even the asbestos is in good shape. I'm in the same boat with my 1937 Arco No.7 Ideal Boiler. I maintain it and leave well enough alone and it operates beautifully.

Option two, upgrade to a new modern cast iron boiler and decommission this old one.