Thank all of you for the input, and I will be returning to the P.1121 but I wanted to get another project underway, a 1960's MBT for New Anglia, our aggressor nation.
So far, the biggest concern seems to be the turret ring, which I keep getting told is too small, though it's larger than that of the original tank drawing I FD scaled, then modified, a Vickers Mk3. My idea was for a tank just slightly more capable than the M-48, but not as advanced as the M-60. This is extremely WIP, so I'm going to get it working first before I start putting any names on it.
Comments are welcome!