The good news is: the first bit of the Q register and the ALU have been wired and they're working! Also proving that the more efficient ALU designs are a reality!

I tested for convenience the full adder and for the logic part the NAND operation, but all other logic ones are straightforward to see operating.

Below for example 1 of the Q register is added to 1 of the bus and a 1 carry in, resulting in a one on a "flying" bit of the R register and a carry out on second bit (note that relay view is upside down):

The bad news is that mounting it with fastons as I did is extremely difficult with "dense" relay utilization...

Faston are hard to slot in, and there is very little separation between them with even the risk of a short circuit on the bottom if two adjacent ones are slanted towards each other.

Boefore continuing to mount the rest of the circuit I've to decide how to mount it. Options might be:
1. Continue in this way, maybe finding a way to at least prevent short circuits (e.g. with a plastic foil between adjacent connected row of fastons)
2. Solder the wires to the relays instead of using faston
3. Buy relay bases and "easily" screw the wires (trashing all the effort spent on the frame, adding one month shipping time to the additional money to be spent)