i was wondering if anyone knows what type of finish may have been used on an '81 L1000 mahogany body fretless? it seem quite thick--perhaps polyurethane? also, does anyone have any recommendations for what to use to clean the body and the neck? and lastly, i was curious about removing the finish (i.e., if this might positively affect the tone, and/or detrimentally affect the bass.)

There's a lot of mystery surrounding finishes. Here's what little I know:

-no finish/oil finish tends to impart a warm, woody tone

-thin nitro or poly finish will add a bit of crispness & attack, yet still allow the wood to speak

-thick finishes tend to dull/mute the tone

If the bass sounds good and lively unplugged then the finish is probably just fine the way it is. If it sounds like plastic then a change may be in order.

That sounds like a refin to me.
I have 5-6 basses of that era, all of which have very thin nitro-seeming-finishes that are very different from the thick heavy poly finishes on Fenders of that era that I won.

thanks for the info!

sure!