I had an engine in a TT like this once.
It has never been stamped. I wonder if this was common in the years before titles. I think titles were started in the twenties in Missouri and this is a 1918 engine, so it could have been put in a car built a few years before this one was made.
Replacement engine blocks were not stamped, complete engines were. The dealer was supposed to stamp the number of the replaced block when doing the replacement, but obviously didn't always do that (or perhaps the owner bought a spare short block & did the changeover themselves?)
The engine in the ebay auction seems like a mess of parts from different years - but there is a possibility it was in a 1915 with mixed pedals from the factory (but not all three types from start, I suppose!) then something happened to the original block in 1918 - freeze damage? - & a replacement block was fitted to the salvaged part of the original engine?
Then over to your engine.. Does your truck seems to be early TT production? (sorry, I don't know enough TT to point out exactly where to look, but Marc Williams at the ton truck club should know: http://www.tontruckclub.org/ )
If your truck is 1917/early '18 production, your engine might have been a replacement block for your truck - otherwise your truck may anytime later have had this engine transplanted from another T who had the repair in 1918.
All cars and trucks had an engine number,later frame number/vin, regardless if the state used titles at the time - just like bicycles always has been numbered even though registrations & licence plates for bicycles has come and gone over time.
I like the home made pan replacement / repair ears.
Those ears are common at good swapmeets. I have a pair that have probably never been used.
My 23 engine was replaced sometime between 1923 and 1926. There are no numbers stamped on it. I've chosen to leave it unstamped, and stamp the numbers on the frame for licencing purposes. Would new blocks cast after 1926 have had the holes for the hogshead to attach to or did they cast 2 types of replacement blocks, one for the pre 26 and one for later application?
My truck is a 1918. It has a 1918 engine in it now.
I think that the beads around the casting of the differential housing are an indication of an early tt truck.