Bear Valley SE first. Crank arms position is interesting! This is how i found it with what kinda looks like a crank arm extractor in it. Hopefully the mud has protected it rather than rusting it.
Well it took 30 mins to strip all the bits off bar the seatpost which took over 2 hours. Does anyone know how Marin do their frame numbers. Took some pictures as best i could but they are hard to read. Apart from the hanger being a bit bent and some surface rust it doesn't seem too bad. Certainly no rot that i can see. Haven’t stripped it yet but it does look like the original headset which feels dry but not too graunchy. Hopefully just new bearings needed. Going to get a tap into the BB to clean up the threads, but again they don’t look too bad.
I don't know about Marin serial numbers, but if you're wanting to know so you can work out which year they're from, I think you'll find that they're both 1995 models.