question about 1911 mags, specifically the Smith and Wesson E series

I know that the 1911 platform has a flush fitting 7 round magazine. My 1911 is Rand made GI issued one from 1948.

I see the E series has a 8+1 capacity. Will a standard 7 round magazine fit in it? Will the 8 round mags fit in mine? Are all 1911 mags interchangeable?

Thanks DC.

in full size frames to the best of my knowledge all 1911 mags are interchangeable and 7 and 8 rounders will fit flush in the same gun

Thank You.