Retrofit AMP meter

The Sunpro 8215 gauge is all over ebay, and can be had pretty cheap. Bosch took over some of the Sunpro line, and looks to still be making the 8215.
Electrical Voltmeter Automotive Gauge | Style Line 2”
Pep Boys is showing it for $5.99. Maybe they actually have it, and maybe shipping isn't outrageous.
Sunpro Sunpro 2" Black Face Voltmeter | 9652699 | Pep Boys