After a bit more research it looks like I can get the 910 running with $20 in parts as there are no extension offices that test gauges near me. The parts would be a new safety blow off and gauge. They do not sell replacement safety blow offs for the 921. This 921 seems to be older, it does not have a date stamp on it to tell exactly how old either. They do sell new lids though which with the gauge and new blow off would put me back $80 there. I’m looking at a ballpark $120 repair shipped for these bad boys!
All my loans are sub 5% so I’ve been putting my extra cash in Alliant Credit Union’s 5.15% APY 18month CDs. No point in paying them down if I can basically beef up my emergency fund as a bonus.