Using the right main vents - Gorton vs others

Inwood Steam

I have three main vents in my basement. None of them are working properly, forcing a lot of air to go through the radiators instead.

The three photos are here:

http://tinyurl.com/2m8fhf

1) This main vent is in the middle of the basement, where a 1" pipe comes straight up to a point that is I presume some minimum distance above the boiler waterline. The existing air vent threads directly into the 1" pipe. I've sealed it up because it is broken and constantly leaked steam (it would not close). I can't read the make or model on it. I presume that a Gorton No. 1 is needed here, perhaps with a reducer if necessary, and if I can fit it next to the main in the photo. At the moment it is rusted into place and I'll need professional help to get it off.

2) At the far end of the basement, the main does a 180 and a 1/2" nipple sticks out. Years ago some genius decided to reduce this and stuck a Hoffman 41 straight air vent on it. I think this is a radiator valve, not a true air vent. The Hoffman was painted over as well. I tried putting a new radiator-sized straight valve on this but it rattled like crazy. I think a Gorton No. 1 is needed here also, perhaps the 3/8 variety (if I take out the reducer).

3) In the boiler room there is a short main that has a bend on it before it goes upstairs. There is a nipple on this bend that fits a radiator-size 1/8" air valve. I've replaced this as shown in the photo and it works ok, though it spits a little water now and then. The nipple is too small for a true air vent - maybe a Gorton straight-angle D would work (they are hard to find near me, but I could order one from the internet)

Does this make sense? I'm fine with my rads but these mains are confusing.