I still have A500 number 92 , feb 87 in my garage. It has the split clock, ARM3 and so many hand wired connections it looks like a bowl of rainbow spaghetti. The original casing got seriously scratched up so I stripped it and painted it a nice rich brown many years ago - I had to schlep it to the US for conferences so often that it wore through the original colour. I added a couple of welded on lugs for a decent handle as well to make it easier to take as hand baggage.
Imagine trying that these days - an obviously not-commercial box of suspicious wires with od switches... I don't think so.
I used it to develop the original Archimedes Smalltalk port that is mentioned in the first public net-mention of the ARM. It lasted me until an A540 was provide by the Active Book Company as we developed a variant Smalltalk for that late lamented tablet. After that came RPC(s) of course as I moved to silicon valley to make more Smalltalk and now an Iyo for developing Squeak.
Wow - eighteen years of making a living developing Smalltalk on ARM/RISC OS machines. Who'd a thunk it back then?