Correct "T" sniper rifle?

[Roger Payne]

It's fine, IMHO. M47C = BSA Shirley manufacture (by far the most common supplier of rifles to be converted to snipers). S51 = factory code for Holland & Holland of London, who effected the sniper conversion. The number stamped into the butt just behind the bolt is the serial number of the scope it was issued with, & speaking from memory it was an early Kershaw Mk3 scope.
The S & TR look ok. A 'G' prefix serial is correct for a 1944 mfr rifle. The body pads do not look to have been butchered or recently fitted. There is, as you say, a little light rust here & there, but this looks to be minor & because the rifle has been stored in less than ideal conditions. The rear sight leaf can't be seen in the photo's but the cursor is SM marked (Singer manufacturing Co.) which is typical. The mag not being serialed to the rifle is of no real concern.

What's the bore like?

Can't really make any valid comments on the hoped for price as you are (I presume) in the US & I am in the UK, but no doubt there are plenty of others who may be able to chip in on this point.

Hope this helps.

ATB