Thanks for comments so far. I think I'll need to do it, because of recent problems AH "leaning" and DI deciding to suddenly spin of own accord. Had suction checked and not that, so maybe age is getting to both of them. Would be a simple fit as would only connect one to new 8.33 Garmin radio so that the GPS would allow radio to show me nearby frequencies etc. No need for any other instruments to attach. I'm pretty sure I'd still look at the regular ASI rather than tape as the scan is drilled into me. Only private use, so no worry about instructor seeing anything (except maybe IR(R) renewal time). At present I still have back-up in that the 496 has an instrument panel page, so might give them a little longer, before breaking the bank. More comments and advice gratefully received!