Thanks for all the input! I'm really glad to hear my vario should still be able to function OK (not hobbled by old pressure transducers or slow CPU).

My Kobo isn't tied to the vario, but I'm going to look into doing that, as waremark mentioned. The odd vertical thing is a G meter, by the way. The dash speaker is inop, there's a speaker in back, so that space is available.. I think I'll just paint, label and maybe rearrange (thx for the suggestions, ND) the panel, and leave well enough alone... for now!