I absolutely LOVE my '95 800 Sport and have been cycling and commuting on it since Dec 2013.
The bike (like mine) should be Cro-Moly Steel. I've flipped it a few times at relatively low speeds an the only damage has been to me!
I've gone from a 3x7 to a 1x9, attached whatever I've wanted (racks, etc.) and almost exclusively from donors, sales and basic good parts. It is a resilient beast
It uses a standard, old mtb seat post, so shouldn't be hard to find. A little search-fu should result in the online pdf for the model, along with specs"
http://www.vintage-trek.com/Trek-Fis...d/1995trek.pdf