Daisy Daisy 747 best "at rest" condition

I have been using a 747 as a practice tool for RF Bullseye this winter and have developed a real appreciation for this air gun. I had to rebuild the pneumatics just recently and wondered if the air valve would last longer if it was in contact with the seat of if it would be better left in the "fired" (valve open) condition while at rest? The previous rebuild went about 3000 rounds & began to lose air. The failed air valve showed just the slightest ring in the delrin but I guess it was enough. With parts so scarce, any tips to extend time between rebuilds would be appreciated. This is an addictive accurate little gun to shoot.
 
an interesting question
and yes you are right parts are disappearing, new valve stem sometimes does work with an old valve
i tell people to not touch the valve at rebuild time before you replace the tube and piston head Orings
of course, if you know the air is leaking out the barrel than you have no choice and that is where the gun could be in trouble because you may never get it to stop leaking
as you know the pistol can leak from three places
the valve to the barrel
the valve stem out the stem
and the tube Oring at the valve
and the only way to find the leak is with a bowl of water and pressure in the cylinder, kind of a 3 handed job
so would i leave it cocked, no i don't think so
would it hurt maybe the springs
it is a 50-50 call in my thinking, i have never read anyone doing it and if that was true ever SSP should be done that way if they could be
the daisy is not like most of the rest of the SSP in the trigger group
i will say it again a good question