Does anybody know anyone that can convert a 1949 ford shoebox 6 volt gauge to a modern 12 volt setup with electronic or mechanical setup in southern california
Do you want to rebuild the gauge or just be able to run 6v gauges aftre converting to 12v? Simple voltage reducer... http://macsautoparts.com/1949-59-ford-mercury-voltage-reducer-v12871/camid/F50/cp/VF0JETSZ1000005/
I used reducers made by Runtz on mine and have never had any problems. That one on the post before this from Mac's looks like it would work well too.
You should be looking at shoeboxford.com and talking to Chris at shoeboxford. Macs and Dennis Carpenter sell parts but Chris offers better service and free advice / information to customers on the best way to accomplish the job. He has forgotten more about 49-51 Fords than the others will ever know. He also knows his way around California pretty well, he used to work at C&G Ford.
... and Chris will ask the OP something like "do you really want to run a modern gauge, or are you just trying to run the original 6v gauges after a 12v conversion?". Why rebuild gauges IF they don't need rebuilding? Sometimes it is just a matter of parts. Chris knows more about shoeboxes than most of us, no question, but thanks for the insult anyway.