When I built mine it took me about a year of parts gathering to find the right sources and ebay parts sourcing. I lucked out with a few gen pushers for almost nothing(Used a pair on the 7032 as well)
Worse case scenario, the Ofrei pushers are not too bad and are gen replacement parts. Always make sure you re-grease the o-rings before installing in the case. Safe assurance that you will be water proof to at least wash your hands and such.
The T21 from Ofrei was actually a good upgrade, although the t21 from Clark's was good as well, I ended up using the Ofrei one(Had a lower profile)