Hi All,
Update 22 May 20
Problem... drilling vertically into the rear plate without mishap (I broke a drill doing this earlier)
Solution... use a B&D Workmate and a smaller mill/drill.
Success....

Next job...machining the rear plate to add the required ‘ledge’ to the inner face. The plate will be “thickened” in due course by adding 1.5mm internally, probably using styrene sheet.
Note the patch added to recover from the results of removing a broken drill.
As I was getting the firewall laser cut I decided to design some Inset plates to add extra ‘strength/thickness’ to the belly plate, my design had reduced this to 1.5mm in places.
Test fitting the firewall. I am only including the detail for the engine compartment as I am planning to fit the loud speakers in the area of the sponsors occupied by the upper fuel tanks on the full sized vehicle.
The next image shows the firewall attached to the cross-member with M2 bolts and the cross-member “cut down” to fit the bearing for the turret.
Test fitting the idler axles. I also attached the idler adjuster covers to see if I can bolt in from both sides. This will make the design of the adjuster bolt capture plate a lot easier.
Next comes the fitting of the partially constructed top plate support bulkhead for the front. I have yet to design, print, and fit the webs.
This view shows the kit provided top plate and the additional area required to fit with the repositioned radiator etc. covers and engine cover. I intend to replace the whole top deck with a mild steel sheet so that I can use magnets to ‘lock’ it down.
I have recently received the excellent HL230 P45 kit from Ivano and will start the basic construction so that I can layout the rest of the engine bay.
That's all for now,
Alastair