My 1957 Oval is coming home

Three years ago I posted this:

Recap: 1957 Beetle sitting in West Texas - bought it. Then it sat in W. Texas at a friend's house for 3 years. I'm finally moving it into my garage in a couple of weeks, and am anxious to get started on it.

Here are a few pictures:

It has the original 36hp motor. I can turn the motor over by hand, so it isn't locked up - aside from that, I have no clue if it'll run, or how worn it is. The pan is very clean. The front and rear look pristine (no evidence whatsoever of any collision damage). Surface rust here and there on body, but no rust-through that I could find, even on corners and crevices. Interior is pretty rough. It's missing the back seat. Channels are solid. Overall it's pretty dusty/dirty. I ended up paying $200.

I don't know how the project will go. I'm partial to original restorations over custom. I'd like to drive it to work occasionally, but realize it will be a lot of work to get it ready. I think I'm just going to jump in and see what happens.

I have thought about crating the 36hp in favor of a dual port 1600 I have stashed, to save the original motor from excess wear, and to boost the power a bit, since I don't plan on keeping this garaged. I want to eventially drive it a fair amount. Any advise on motor choice?

How about brakes? Upgrade during the process of getting it running/driving? Keep it 6V? I hope these questions don't seem too sacriligious.

How much is another back seat going to cost me? Are they hard to find?

Thanks for any advice - James