SOLVED - oko143 : Terry Mitchell Special aka Mongrel

[Allan L]

Morris XPJM and MG XPAG engines are quite similar in  appearance. I think the four-two-one exhaust system implies a non-MG cylinder head such as the Laystall-Lucas which did have four exhaust ports.
Morris Minor front suspension with coil springs is a bit of a puzzle, but "custom" bottom wishbones is presumably the clue.

[gte4289]

That's not the puzzle car but another special built by Terry Mitchell, this time with MG engine and front suspension.

Ah yes, I see that now. It was included in the same two-part article on Terry Mitchell specials.