So my Mooney (knicknamed "The Mooney Pit") was in the shop this week for it's annual. My A&P wanted to be proactive and replace the O-Rings on the fuel caps even though they weren't leaking. I agreed until he struggled to find replacements and then searched for the whole cap as a replacement. To our surprise the cap itself was available for $5,500. - we quickly figured out that the two gas caps on my plane are worth MORE than my plane as a whole!?!?!
Needless to say I love my Hatz even more... maybe it's time to make a canopy cover so I can fly her more in the winter.
Yes it appears that i have the same affliction as you I'm looking for a open bi-plane for fun flying.
You have bladders on your Mooney?
I have to check with my former mechanic but I think she has a part number for the O-ring which is an odd shape.
I can't remember which par of the country you are from. I'd love to see you Hatz and go up with you if you are relatively close.
I do have bladders in my Mooney, we decided not to replace the o-rings since they weren't leaking anyway. I am at KVUJ - Stanly County Airport in Albemarle, NC - if nearby let me know and we'll go up in the Hatz.