03-A3 Identification Question

I've got an 03-A3 rifle that my father built for me back in the 1970's, and I'm trying to figure out who manufactured the receiver on it. I really would hate to have to take the scope and scope base off to see if there are any markings underneath, so let's see if we can do this by using just the serial number. The serial number is 5032*** on the receiver. We used an 03/A4 barrel on it, with what looks to be RA over the ordnance bomb over 8-44. I appreciate any help anybody can provide.

From what I'm finding online, this serial number was allocated to Remington for 03-A4 production:

"On 20 June 1943 an additional 8,365 M1909A4 rifles were ordered. "Block" for these rifles and possible future orders were 4922001 5784000. After this block had been used to 4997045, receiver marking was changed to "03 A4" and a new series of numbers begun with Z4000000."

I think there is a misprint in that, where they identified M1909A4 rifles, think they meant M1904A4 sniper rifle.

Based on this, my receiver may be one that was produced by Remington, stamped, but never assembled due to the designation change after serial number 4997045 (about 35,000 numbers difference, consistant with their 1943 production rates). I know it was an "in the white" receiver when dad purchased it for the build (in original military preservative wrap).