These people helped us.
There's not much that they don't know about showers and there are plenty of exploded views to compare with your unit:-
http://showerdoc.co.uk/index.html
Eberspacher heating
I bought a secondhand D1LCc on Ebay and fitted it at the start of a very cold winter week aboard.
Everyone appears to have their own opinion on diesel fired blown air heaters (usually based on their own experience). In that respect and after 4 years of faultless service I...
Your heater is described as a "D1LC Universal 24V"
It's full part number is 25 1768 05 00 00
It does have an external control unit (part no 25 1689 50 00 08)
edit|: post was in reply to pcatteral (not sailorman)