Let me answer your questions:
1) The width of the rib is 3/8". I think any of the standard .22 / 1" rings with the allen wrench screws should be able to span the rib. Get the solid alloy rings and avoid the sheet metal cheapies. There are lots of choices on Midwayusa.com.
2) More importantly, the length of the vents is about 5/8 inches. That is the important dimension because you need to look for rings that are that width or smaller.
3) Sorry, I don't see a brandname on my rings. I think they were a give away with a scope. But, as you look, keep the vent length / ring width above in mind. There are lots of choices on Midwayusa.com. Generally, those rings that use two screws (one on each side) to hold the top bracket in place are narrower than the ones that use four screws. Worse case, you can file down the claws to fit.
4) I don't know if a RedDot for a .22 dovetail will fit without tweaking. It depends on the claws are solid across the lenght or split, and whether the claws can be adjusted to fit the vents. I'm sure you can do some crude machining (my style -- file and dremel -- the limits of my mechanical aptitude) to make it fit.
5) I have the .22 mag / .22 LR combo. You can buy separately, but NAA says you need to send in your gun for a fit. The combo price is actually very close to the price of the LR only. Check out thegunsource.com. 22 LR is great for a lot of purposes. For survival, I'd pick the .22 mag. Just consider that you can carry a scoped revolver and 50 rounds of ammunition, all weighing in at less than 1 1/2 lb.
One thing I need to figure out is the trigger. It is different and a little funky. I am going to experiment with different trigger finger placement -- tip, joint, second segment, etc.
Good Luck. I'm sure you will greatly improve on my crude prototype. Let me know how it goes.
Interestingly, NAA apparently once considered creating a scope mount to fit the Mini Master, but never got around to it.
Best Regards,
RFC