I doubt AL is going to suggest a rebuild kit for it, it's pretty old. The good news is, the soft parts are all common parts so you should have no problems finding replacements if you want to DIY a kit. The Oring is common, the LP seat is common to a lot of modern regs (or you can make your own) as is the diaphgram but odds are it's OK. The biggest problem will be the exhaust valve and odds are it's a common size as well. Trident has aftermarket parts that should work in their catalog, any dealer can order the parts for you.
Well duhhaa, as I closed this I realized you said first stage but since you need both stages I will leave it. The DS is a simple flow by piston reg. All the parts are common with the possible exception of the HP seat. The seat may or may not be common to other regs (odds are it is). If I had to bet, I would guess it is the same as the Aquarius (also no OEM parts). If it's common Trident also has seats, if not you can DIY them fairly easily.