Welcome, I hope you will enjoy shooting with the Pentax 6x7. I have the newer "67" but apparently it is almost identical to the earlier "6x7" versions. You might want to consider getting one with mirror lock up (MLU) if possible, it's a useful feature.
When you say the body is "battered", does it appear to be only cosmetic? Like brassing of the paint etc? 6x7/67 bodies are quite readily available and affordable, so don't feel that the local one is the only one available
I can't offer much on the other points sorry.