who is the U.S. distributor of older diana parts?
springs,seals. exc..
looking for parts for a model 50
and anyone have the address?

or know where to go to get them.

I doubt that the Diana distributor is needed (or desireable) for servicing a Diana 50.
It may be adviseable to review previous posts here re Diana 35 & 50 rifles.
#1 There is a required sequence for disassembly to avoid breaking the trigger.
#2 There are tips which will greatly assist in reassembly.
#3 Diana distributors will supply an overpowered replacement mainspring which is totally inappropriate. James Maccari and others can supply more suitable springs.
#4 Diana 35s & 50s have screw retained leather piston seals which are secured by a pin drifted into a blind hole. They can be difficult to remove without damage. The leather piston seals can usually be rejuvenated by cleaning and relubrication.

the need for parts was due to a house fire, the leather washer/piston seal was damaged by the heat..but luckly the bore wasn't damaged
the main spring is still functioning but i don't know of any loss of temper in the spring,, so i'd rather replace it also, while i have it apart.
thank-you for your responces...
jeff

I'm looking for a distributer too. Pyramid Air has quite a few diana parts for sale on their website, but I need a rear sight assembly for my 350 magnum and can't seem to find one there...

but you should be able to find springs etc. no prob

I have also checked around for parts for the older Diana guns, so far Umarex had a very limited supply, I also checked with Beeman as they used to sell some Diana guns and not much luck either. Chamber gunmakers in the UK has a pretty good list, problem is when I asked to order from them they were not so inclined to sell unless I could provide Sterling GBP for payment. It is a real problem actually to find parts for these older guns. Ounce a gun is no longer made replacement parts are no longer made from what I have known for years. I checked and it looks like your piston seal in your 50 is the same part# as the 35 used which I can tell you Umarex does have one of those. the problem I found is the trigger has to come off at least it would on my 35 to let the spring and the trigger parts inside of the end of the compression chamber out. That pin is staked in or flared over on the ends to keep it in. That trigger spring that is in there at the back end is a pretty stiff spring and if you drove that trigger pin out more than likely it would enlarge the holes it goes through, you would need for shure a new trigger pin, I have not been able to get my hands on one yet anywhere. I have no idea if the trigger pin could be held in then, it would be a hardened pin and you could try to flare it back over on the ends but if it came out, the trigger would wobble the spring would jump out more than likely and not catch when the gun is cocked. Now I noticed the complete trigger assembly for these guns does have the pin and spring both, if I ever find a new pin I would then see if it is possible to replace the pin on one of these guns. This is what I know so far owning a model 35. Your best bet is to try and locate the parts you will need, then proceed from there, the other thing is when you pull out the mainspring you would want to make shure you put it back in just the way it came out, don't reverse it or anything like that, stress the sping in a different direction and it might not hold up to well again. I have left my 35 together and oiled the piston seal with chamber oil and let it soak for a while my guns seems okay, but if one needs to work on one of these guns and needs parts it is a problem that is all there is to it.

UMAREX had the parts in stock.......
call on the phone they were extreamly helpfull.
second comment.. as for disasembly
you are really overcomplicating your disassembly...
trigger assembly comes out with one pin..hardened,just tap out with a brass drift..(note assembly, not taking the whole trigger apart but the whole assembly)
mainspring.slight compression of the main spring from the rear and the cross pin pushes right out...not staked in or flared over on the ends to keep it in.
the pressure from the spring holds it in place..the biggest problem is the three little balls that are in the rear assembly getting them to stay in place was a real bugger,tried the old vasoline trick didn't work, but went to using an strong magnet on the back of the block and that seemed to work well.
now to finish the custom stock and i'll be set to go......
thank-you all for your comments

You are also correct on the disassembly. Someone told me JM clear moly works to keep the trigger balls in place.

"but I'll be needin' that gun, fer squirrels and such."