Update....
Ran the machine all winter with no brakes. Worked well but not something I'd recommend. Hired a local mobile mechanic to replace the foot valve (since it was stranded away from my shop) and his new one (its an off the shelf Bendix piece) holds pressure but keeps sticking on the torque convertor release circuit.... he was supposed to return with another replacement and hasn't shown up in a month plus. Haven't paid him a dime. If he didn't have my manuals I'd just tell him to stuff it at this point.
It is a slow machine for snow pushing. Ran it in 3rd gear mostly, though when it got heavy it would really bog the machine down (but not the engine speed). Dropping to 2nd makes little to no difference, and 1st is just creeping along. Tranny temp never gets out of hand though, so I don't think its slipping excessively..? Just struck me as odd. If you over do it with too much snow it will spin the tires and stop in its tracks, yet it pushes along very very slowly. As long as I stick to 2/3 width of the pusher (and we're talking about a long push here!) it seems fine unless its wet heavy concrete-like snow. Wish I had another to compare it to.
Never did get my new tires on either.
My ether start system.... I ended up building from pieces sourced on ebay and a cylinder from the local truck shop. I've got about $50 in it total, so not bad at all, and it is entirely new pieces (plus 5 or 6 spare NOS valves). I ran out of time to wire it to the dash but two alligator ended test leads to the battery worked fine. LOL
I installed the new brake drier system too, works well. Though in doing so I found the battery drain--absolutely nothing but the starter is tied into the key. EVERYTHING ELSE on the machine is direct, including the drier's heating element and the alternator, so no wonder it goes dead when the cables are left on. One of the four brand new batteries was bad as well, so it was hauling down the batch when it sat disconnected. Exchanged it the other day under warrenty. I'll be adding a master cut off switch to the battery cables and doing some rewiring this summer.
All in all, it ran strong all winter, just wish I'd had a little more time to prepare beforehand.