The Musical Fidelity A and P series amplifiers were popular in the UK in the 80s and early 90s. They had a reputation for good sound but were let down by poor reliability as some of the components were run within an inch of their rated spec and sometimes a little above which given some of them, the A series, were quite heavily biased and produced a lot of heat it was a surprise some of them lasted as long as they did. Anyway here is my take on it, the original used an LM318 which was a fast noisy op-amp, better devices exist today and an OPA134 0r OPA604 would be a sensible choice as a replacement, as I am not sensible I chose the ultra fast OPA828 which is a 150V/us device which does however work well. Some pictures of the real amp and square wave test, bench PSU limited to 2A but still not bad. Kicad files for the brave attached, how does it sound?, IMHO very good been listening to it for a few weeks using dual die FETS and 400mA bias and it sounds very good, dual mono very good imaging, no nasties, up there with class A, current dumping design and a Pass Sony VFET V2. Obviously it can be DC coupled so watch out if you try, it has the advantage of lateral MOSFETS is they can take heavy bias currents, heatsinks permitting, without thermal runaway. Do not use vertical devices, they are not suited to the design and will probably blow themselves and something else up as well you have been warned! plus the drain and source connections are different so you would need a PCB redesign anyway.
