Try snipping off about 20cm in the dark then chop that in half. Put half straight in a dilute developer for five minutes then fix and wash - see what, if anything, is edge printed on the film and look at the amount of fog. This may help date what you have and decide if it is worth going further. The undeveloped piece of film can be examined closely to see if it is gelatin-coated both sides, has emulsion both sides and so on - that may help you with the practicalities of using the material.