Capt. Vancouver's 40s Path Racer H.M.S. Discovery

Raleigh/ 22"/ ?
Cheap/ Nitto
Stock/ Stock
Shimano/ Araya/ Kenda CX 27x1 3/8
Formula FixFree/ Sun CR18/ Kenda CX 27x1 3/8
Raleigh Heron (Cottered)/ Stock
Motobecane(?) Leather/ Stock
Wellgo platforms + Christophe clips & straps/ SRAM PC-1
Shimano dual-pivot/ MTB lever
46x20/ Trek rear rack & Lone Peak pannier/ SKS P45 Fenders
Found it hanging in an old man's barn. He bought it in 1948 as a fitness machine from a bike mechanic. Rode it for "twenty-five years or so." I tuned/ lubed/ cleaned it up and replaced some parts that were trashed (brakes, stem, front wheel). Added a bottle cage. Rides great with the fatty road tires, rolls over everything. It fits me too well to not become a major restoration project. I gonna build up a custom fork, paint it up all purty, get some better bars.
I'm having trouble dating the frame, or determining what model it is. The serial # is on the bottom bracket, stamped along the drive side cup, unlike anything Raleigh is known to do. The maroon color is not stock, it seems to have been navy blue originally. I think it might be a pre-WWII Record Ace, but I have little to back up that claim, as cool as that would be. A late 40s era Clubman perhaps.
New pictures later today if the sun comes out.