Heads up on the Whelen LED rotating beacons.
The 70900-04 is the drop in replacement that fits the stock beacon housing on my PA-39 (and Kristin's 30). It no longer shows in the Whelen catalog but is available.
The replacement that is in the catalog is 90520-55. It will work but creates a moat environment for water to sit in the housing.
If you want to spend the more money, the Knots2U slimline housing will take the 90520-51 LED from Whelen but of course, requires potential fitting and painting.
Yes, I learned all this the hard way and so did Whelen. They did stand behind their product and will send me a 70900 to replace the badly fitting 90520. They declined to pay for the extra shop time it took because we also were lucky to get a mis-indexed 90520 but are sending complimentary landing lights - which, with tip tanks, costs more to have the shop install but worth it in the long run.
Hopefully by posting this another Comanche owner can avoid this problem.