Thanks JCB. I do shop there a bit they used to list 4mm but it's no longer an option. I'll give them a phone.
Here are the Kyosho Towers designs. All mountings are the same and I've added the new rear shock upper mounting holes as you asked. I've also added in more material, less inner structural holes so the towers have a bit more strength.
If you can think of any alterations let me know. Gonna get these sent to my brother for milling soon.
J