Ham's '48 - Engine Number and What is it?

I've had this engine for 40+ years and we spent the last 2 years in a restoration and until now we never had a good idea of just what the engine was. I know I got it in about '73 - and it was a replacement for the last L-134 flathead. But - it was just an engine.

Everyone knows (!) that Jeep engine numbers are stamped on a boss behind the water pump. But, what if the head had been planed and the number erased. Well, if you're lucky, maybe someone stamps it on the block.

I was touching up skinned paint yesterday and I found this number (after looking 40+ years) stamped on the side of the block above #1 exhaust port.

I can find all kinds of engine serial numbers for the L-134's used in military and CJ series, but I've not stumbled for a similar set of data for the F-134 series of engines. Is this a valid engine number for an F-134 - and what did it come from?

OK guys, any help here?