I recently bought an old train set which included some Märklin items (ES 800, CM800, and 3024) and in addition to those, an old 3-rail Liliput tank locomotive and a Shell tanker.
I believe the Liliput loco is item 111 based on images found on the web. It is very heavy and it contains a "Wehrmachtsmotor" - a very well built motor that was available after WWII.
I opened it up and cleaned the old grease off the worm gear and applied new lubricant. I hooked it up to DC power and the motor runs amazingly well. Very nice slow speed running which is hard to match!
The Connecting rods have the name 'Liliput' on them and seem to be made from Aluminium.
I am not sure if the cylinders, window frames and some of the pipes were painted red by a previous owner or if it left the factory like that. Certainly the wear it has endured was well after the red paint was applied.
The frame was held onto the chassis by buffers that thread into the chassis, and three of the four are missing, the rear two having been replaced with small bolts.
There are also small headlight lenses but no lightbulbs are inside anymore.
The pickup shoe has been replaced with a Märklin one.
It is thought to be from the late 1940s or 1950
Overall I am very impressed by the locomotive given its incredible age. I am not collecting Liliput so I could be persuaded to sell it!