Comanche parts availability is often better than newer planes as Piper back then borrowed so heavily from the automotive industry. That a few dedicated suppliers and a very active grassroots organization, keeps the aircraft flying along well. The owner base has been able to advocate vendors to provide upgrades. For example, much lobbying got Garmin to certify the GFC500 for the Comanche and Twin Comanche. They were apparently dubious that they would get more than a dozen orders, but reports are that they have sold over 100 so far, so our street cred must be good with Garmin.
Truly competent Comanche mechanics are a bit more of a challenge. They are out there, but a new owner really needs to be plugged into the group to learn who you can go to for some of the things you are likely to need. Also, likely any complex, vintage airplane, a prospective buyer would benefit from knowledgeable, pre-purchase guidance. Two of the better online communities are the Airworthy Comanche forum -
http://forums.delphiforums.com/comanches/start - and the Piper Comanche Facebook Group -
https://www.facebook.com/groups/68675657216/
If you are at OSH this week, mosey down to Comanchetown, which is down by the ultralights, about row 98-99. You can find folks who will answer your questions. You can PM me if you want to know more.