A correctly marked 03A4 will have the serial number offset and be marked "03A3" (yes "A3") offset as well, so it can be read with the scope mount in place. It's a completely different marking than on any other Springfield, so it's easy to spot. I don't know the story of why an A4 says A3, but that's the way it is. There is no such thing as a 03A4 that will say "A4".
The original scopes used were the M73, then the M81/M82, and then finally the M84. The M84 was adopted for use on the A4 in early 1945. It's probably the best scope out of the lot, though frankly they all stink. I mean 2.2 power and rotten US optics. Even back then it was a pretty sorry scope. I had one on a Springfield and it was cool and all, but I replaced it with a commercial scope after the first time I shot it.
They command a high price, but they are a very nice gun.
Ross