I think you speak too soon young grasshopper. Below the crown there appears to be the telltale GRI, which will indicate Indian manufacture.
The 2a 2a1 rifles weren't around until the early to mid fifties. That may be an Indian receiver but it is way to early to be one of the rifles with the tougher receivers. 1917.
I have never seen one of the 2 series recievers with such an early date or a date before the fifties.
sorifern, get it checked out. On the other hand, if you are going to hand load for it keep your loads below 47,000 cup and you should be good to go. The difference in velocity will be minimal anyway.
The 7.62 Nato round is almost identical in down range performance to the 303 British. Same goes for the 30-06 when loaded to military specs. All of them are capable of producing higher velocities and pressures with modern components.
If you use common sense and keep your loads within those specs, you should be OK.
Check the lug recess in the receiver and look for any set back. If there is any, it will be easy to see.
That barrel has the rear sight of a 2a1. Everything about the receivers made prior to the fifties, is identical in every way to the latter receivers. All parts are interchangeable.
I have even seen a 2a rifle with a 303 barrel on it and a replacement magazine. Why you ask???? Because some of the 2a and 2a1 rifles that came into the country were in very poor condition with very poor bores. The No1 barrels just screwed in and a bolt could be just as easily replaced. A new bolt head/extractor would be needed as well for headspace and extraction.
Same as your rifle, does it extract 308 cases???? It may need an extractor with a longer claw.