It's just a case of EAL wood and barrel assembled onto an available No4MkI receiver, by "joe sixpack", not a/the factory...especially as the receiver isn't complete.
Not a big deal, one friend of mine has sold at least 2 1941 dated Long Branch receivers which were un-serial numbered...and never were...much like yours, in fact it might have come from the same source.
In my junk, I have spare complete stock sets for EAL "military" and EAL "commercial" varients...
I have an EAL with a destroyed receiver which I am just waiting for the right moment to transfer it's parts to an EAL receiver which came assembled (no not by the factory, I know who assembled it, and he is extremely active on CGNs Milsurp sales section and shows up here too) as a .22
If we want to continue playing fantasy games, I could assemble my EAL parts onto a Long Branch No4MkI*(T) receiver....hey it would be 100% Long Branch SAL/CAL and therefore correct right? It certainly would have military and factory inspectors stamped markings...