A slow start to the week, continung assembling the top panel and a trial fit to see how the connections need to be altered to to allow for the replacement switches.  As a result I reduced the length of two brass connection strips to the switches and carefully drilled a new hole in both strips to take the screws that fasten them to the switches.   Next I made two new brass strip jumpers to feed the B+ rail to one side of all the switches, using heat shrink to insulate them.  A trial assembly of the top panel revealed that there was no way I could match up the brass strips to the new switches, so an alternative solution was required.  This involved bridging the gaps between the power distribution board and the switch terminals with soldered connections.   At last I was making progress and I was able to fit the outer top panel and start testing the circuitry with a battery charger.  I soon found a few poor connections that needed cleaning up with a tiny wire brush in my minidrill and gradually sorted them out.  The main culprits were the fuses and their holders, so made a minor odification to three 10A circuit breakers so these would just plug in to replace the unreliable fuses.  At this point everything seemed to be working.