Yep, in fact I have a Shurtron 715-006 in front of me right now that I use as a DC power supply for bench testing. As I recall, I took it out of a 1978 Sunrader
It has a 120vac/15 amp Push-to-reset breaker and a an unmarked circuit breaker for 12VDC. As the tag sez 15 amps DC max, I'd bet that the DC breaker is also 15 amps.
They appear to be standard components in this package size: Boat Marine Panel Mount Circuit Breaker Push to Reset Switch 20 Amp | eBay
Should be an easy part to find locally.
I'll bet that this anwer surprised you..... LOL