Why not just get a real KX-170B?

I did considered that. Although I"d be giving up the digital flip/flop
I'd be getting a much more reliable radio (according from our local
avionics shop). However, they just told me that there are many KX-170B
parts that are now also getting pretty hard to find. Since MAC1700 is
no longe producing parts, it looks like MX is the only company
currently producing parts for 170B replacements. . If I could just
convince them to service my old one. Its actually quite a funky radio.
The buttonology is just different than anything else. The top of the
radio is comm and the bottom is nav. However, the top knob works big
numbers and the bottom works the decimals. There is a C/N button that
flips between com/nav for the knobs. Not what you'd expect. Also, if
you turn the nav off the display is still active. The display on the
nav turns off when you turn the comm off.

-Robert