Fred,

I second DF4's recommendation for Stein air. Excellent service, they know what they are doing and have a solid background and a tremendous interest in experimental aviation. They have been my go to guys for encoder calibration also.

As to adapting auto fuses to aviation use - maybe some have been done with success; however, I have seen a few more corrosion issues/high resistance connections with auto fuse holders and adaptations than I would care get involved with. Just my opinion.