I have 7.3 PSD IPR backup and o-rings if anyone needs them.
I am in Eden Prairie and will gladly meet with you to give you some if you need them. I will also gladly mail some out to you for those of you outside the Twin Cities.
These backup and o-rings were bought to replace the ones on the IPR leekingen was kind enough to lend to me. The thing is they come in bags of 100 so I have more than I know what to do with right now. The o-rings are made of Viton and the backup rings are PTFE. They should be as good as or better than the factory rings. It took the supplier three tries before they got me the right sizes though.