waterman...I can say that 1917 US Enfield rifles with that stenciling you describe was used on 1917 rifles that were sent to England by the USA for Brit use during WW2. The marking was applied in England .
Meant to be used as home guard, C/D type weapons, they were prominetly marked as such to try and avoid a mixup with 303 ammunition destined for P14 Enfield rifles already in same use on the home front there and familiar to the locals from the earlier war.
There is a portion of the left wall (top edge) on 1917s at the rear that is relieved to assist in charger loading,,I'm not sure it's also on the P14.
Another possibility is the conversion of P14's to 30-06 caliber though I can't come up with a reason why it would be done or if done, why it would require the left rec'vr wall to be altered.
Perhaps they were in fact 'reject' but shootable 1917's and sent off the England for guard duty weapons.
