I will likely forego food and shelter for a time but, ultimately, I decided to swap out both vacuum instruments for g-275s since work needs to be done on my failing King/bendix HSI unit anyways.

Justification (my mental gymnastics to justify this ):
1.) More reliable.  
2.) ready for auto pilot upgrade (someday)
3.) plane resale value

Question:  Would you keep the working Attitude indicator and mount it as a backup in the panel  or just ditch the vacuum system altogether? Any other suggestions on things to do while the panel is ripped apart?

I'd scrap the vac system. Does the GI-275 have an internal battery back-up?

Scrap it +1.

Why did you decide to go with dual 275's instead of the low cost Aspen unit? Or said you not even consider that? It's essentially the same price.

Yes, the G-275 does have an internal battery backup. Still, it seems reassuring to have something that works as long as the engine is running as backup.

I really didn't look beyond Garmin as my plane has the gtn-750 and I hope to install a garmin 500 autopilot (someday).  It may not be necessary, but I like keeping it all in the same family.

Vac systems are archaic and removing it is one less maintenance headache to deal with.  Also, you may be able to add another alternator in its place to provide redundancy in electrical power.

Vacuum pumps can fail.  Pneumatic hoses get old and can start leaking.  Pneumatic filters can eventually clog if they are not changed regularly - I've found foam filters that essentially rotted away because they hadn't been changed in who knows how many years, and cannister filters with install dates showing they had been installed over a decade earlier.

It's a system that shouldn't fail just because your alternator failed, but it's not a guarantee that it will work as long as the engine is running.

Sweet!

Ditch the vacuum system with dual 275s.

Decided to delete vacuum AI and vacuum system.   Will keep the pitot static instruments and my autopilot requires I keep the electric turn coordinator.

It will take about 2- 3 weeks to complete installation.

Should be a step toward a more modern panel, can't wait!