Ammeter to Voltmeter...who does it?

Anyone have feedback on Cen-Tech gauges from Harbor Freight Tools ?
Many of you know I focus on a-body rallye panels mostly.
The amp gauge in these panels has a pie slice shape screen.
Transplanting that screen to a aftermarket volt meter would require the meters' 12 volt report to be at the 12 o'clock position and a short sweep..The Cen-Tech volt meter meets these needs.
I've figured out the transplant.of both screen and pointer from the amp gauge but,I'm using a volt gauge that sells for less than 10 bucks. In that is my query/concern.
Any input will help.