Does anyone recognize this shock?   Took this off of my new to me 1994 K75S, PO did not mention anything (perhaps I should have asked!), I know it is clapped out, easily bottoms out, scary when pushed a little.  Curious more then anything, it does not look rebuildable, the only text on it is '18'. 
   Will have to source out another new or used rebuildable one, with some ajustable damping.  Any suggestions, I see lots of talk of progressive springs online but was leaning away from that. 

That appears to be an OEM shockie and if clapped out is not worth anything and should be replaced. There are many options from Progressive, RAM, Ikon, Hagon, Ohlins, BiTubo and others. A good peruse of the forum's search engine will turn up much discussion of the forum member's favourites.