Marsh Vapor System

moneypitfeeder

Hi All, I have searched high and low and have come up dry for a Marsh Vapor System piping diagram. This summer I have to have my near boiler piping redone, and due to the fact that the last boiler was replaced before I bought this house, I don't know what was originally here, (though I suspect the water level was much higher than with the replacement boiler). I have a strange setup of piping to be sure, and I wonder if it is because of the "marsh vapor system" I'm pretty sure originally the return trap and air vent were meant to vent the steam out of the dry returns, (unlike all other vapor systems I've seen that were vented with a trap between the end of main and dry return), but I know the return trap is most certainly not working. The ends of my mains drop into a wet return (and do not cross over to the dry) and the rads all drop into the dry return (which is piped to a beast of a return trap) My boiler has in the last week called for water from the lwco at least 4 times. I have no water in the tank looking return trap which I believe used to collect the dry return condansate to give back to the boiler. I have a strong feeling that is due to the new water line being much lower than the original, so  I would like to see the original layout to confirm or deny any of this. Sorry for the long post, but if anyone has a Marsh diagram, I'd love to see it. Thanks!