Have you got the game played in the late 60s early 70s a sort of cahllenge match between Southern League and NPL champions. I think we lost at Moss Lane!
Think you might be getting confused a bit here.
Apart from anything else, Alty never won the NPL did they?!
If it was the Gainsboro match it was in the build up to the NPL. We played them as Cheshire League Champions (It was before the end of the 1967-8 season when we finished runners-up to Macc after winning it the previous 2 years) and Gainsborough were Midland League Champions. The match finished 3-3 I seem to recall.
We also played another friedly against the Lancashire Combination champions, Morecambe, and got absolutely battered (I think it was 4-0, but I could be mistaken)
That was my first real reality check as an Alty fan outside the parochial environment of the Cheshire League!