Those rifles were sold by International Firearms out of Montreal back in the late seventies.
You had options, purchase one already in the stock, which was a great deal, because International had the work done in the UK, before entering Canada and they only used FTRed rifles for them. FTR = Factory Thorough Repair or rebuilt to as new condition.
The other option was to purchase a rifle from their stock on hand and a stock, then do the conversion yourself. Saved about $20 at the time, but the only guarantee of condition of the original rifle, was what you paid for. They were sold as NRA GOOD/VERY GOOD/ EXCELLENT and you paid a bit more for better condition and for $10 they would "hand select" supposedly for the better condition on the pallet or in the crates. Usually it was a waste of $10.
Tiriaq called it right, M38. Your rifle has be drilled and tapped, so getting the bolt altered for a lower scope would be well worth it IMHO.
Best option, would be to get the arm bent down and a machined knop added to the tip of the handle.