Update:
Ok, the avionics shop called back and said it's going to cost $712 to fix the MK12D. The channeling switch needs replacement as well as the display. The owner wants to settle the transaction now, so he said he'd take $800 of the price if I bought the plane now and assumed the responsibility of the radio.
Wellllll, that obviously entails taking on some more risk, but after talking with the avionics shop (Eastern Avionics), I think it'll work out. If they find anything else wrong with the unit, it'll cost more than the estimate, but they don't suspect to have any problems. Estimated completion time is 2 weeks assuming Narco's got the part in stock (will hear word about that by the end of the day).
So, it looks like I'll have a new plane by next weekend. I don't have time to fly up this Sat/Sun to grab it, but it sounds like the owner is OK with settling the transaction on Saturday, 16 March. In the meantime, the avionics shop at the field where the plane is at is installing a new Signtronics intercom (for only $350 parts/labor!) and additional cigarette lighter near the pilot yoke so I can plug the ANRs or yoke-mounted GPS into without dragging wires from the co-pilots side. The mechanic already installed the new HT hinge bearings, bushings, and bolts/nuts (w/o my consent). He said, welp if you end up buying it, pay me for it. If not, oh well I'm retired and it kept me busy for an hour. lol Very nice guy actually. I just hope he did a good job on the pre-buy and nothing too serious pops up anytime soon. We shall see!
Ahh, and I also found a paint shop near me that will mix me a quart of good polyurethane to match the rest of the engine cowl. The first thing I'm doing is painting that one section of the cowl to match the rest of it! The instrument panel is getting refurbished immediately after that, then should be good to go.
Looks like I'll finally be a "real" club member pretty soon though!