You've done good detective work, almost there. It's a combo switch and 10A circuit breaker, which can be hard to find and are expensive.
Mechanical Products
Series 24 2-pole, thermal CB, snap in, panel cutout 0.85"x1.75", rocker with guard, no light, 10.0A. You could get a 2421-400-159-1000 which has both splash and actuator guard and rip off the splash guard.
TE W33 Series is very close and the datasheet says it fits the opening. But start at $110 ouch.
Or you can split it up, put in an ordinary rocker switch and add a circuit breaker. You can even add a light.
I use the Potter & Brumfield/Tyco/TE
W58 Series (thermal) for transformer protection, they are lower cost. Then you just need a big honker rocker switch.
edit: "... fit into an industry standard cutout of 1.734” x .867” [44.0mm x 22.0mm]. "
Carling Technologies has the L21 Series (although like Littelfuse, many are rated for cars and trucks 12/24VDC only).