Hood Mounted Tach

Take a look at these sites. Might give you ideas or options.
Tachometer Repair Restoration for Antique Classic Cars Auto

AccuTach Company

( In 1 of the forums, "The Tachman" stated he no longer repaired Dixco tach due to parts/supplies have dried up...?)

If nothing else, might be able to pick up a little knowledge to point you in right direction. Hope it helps.

If all else fails...
https://redirect.viglink.com/?forma...MP9a9cT-uITGp2aVTtafZFZ2OzPmSkPJycUREgt-hepb8