Trying to identify gearbox

Searched for gearbox to no avail 



September 1987 Golf cabriolet clipper 1.8 8v manual 4speed
Slow fluid drip on bottom of housing 

Could someone help identify if it's OE please 

The FF gearbox is a 5 speed gearbox and fitted to cars from 1979 to 1983 so it's not the original gearbox, I guess it would of had a ACD gearbox?

There's a paper sticker in boot on the cross brace with the gearbox code on it along with the engine code, paint code and trim etc..

Info on gearbox code etc..

https://www.4crawler.com/Diesel/VW_020_transmission.shtml

Another great website with everything you wanted to know and do with a 020 gearbox.

http://brokevw.com/

Thank you very much for that 

The sticker in boot states code AEN so  been swapped at some point.
Got the car last week for a bit of a project and for a summer run around etc
Got quite a bit  to do to get it running well but enjoying the process so far.