Finally I have tackled the bulkhead. I have used my fibreglass copy of the original bulkhead that I made some time ago. I was determined not to drill the holes in the frame and use bolts. I decided to bond the fibreglass to the frame with the Tigerseal and I have added some additional brackets that fasten the bulkhead to the frame on the sides and the back side of it. I'm pleased how it turned out.
After this I used aluminium sheet to clad the bulkhead. It was a challenge for me to do this, but I'm happy with the result. I still need to insert and glue/rivet the battery box and finish fettling with the master cylinder plate.