Unlikely but yes. If you went to a GMH spare parts dealer and ordered a 308 replacement engine or short engine whatever NT they could get you, you could buy. If they happened to have a 1975 cast NT long or short in stock that is what you'd buy as it suited the car.
As a factory replacement warranty engine they would most likely have given you a current spec 308 for an LX or HZ which was a 9.4:1 engine (bigger dish in the pistons and I think the cam was retarded on the timing gears), almost definitely if it was a long engine as the heads are different. But the 1975 spec NT 308 would still work fine just had higher compression, whack on the HZ or LX top end and sump and away you go. As it says NT it is suited and the number sequence isn't specific to any series.
I remember going in the Young and Green in Kotara in the early-ish 80's. They had about 10 red 6cyl and V8 replacement engines and shorts sitting just inside the door as specials. From memory it was because the warranty period had finished on anything with a red so they were going cheap. I remember seeing a 161 amongst pre and post pollution 202's, plus a couple of V8 shorts. I wish I could tap into that memory and see the Nx engine numbers on them. Young and Green were a pretty big chain of GMH dealers and this was their main parts warehouse so I guess they must have kept a few in stock. I could have easily bought say a HQ NL engine and whacked it into an LX and it suited it just as well as any other NL.
Conversely, a 1978-9 cast red 202 replacement engine is also valid to have been bought in 1979 and stuck in a HQ. Or you actually ordered one fro a HQ in 1979 and they made it for you.