I managed to get the back scene board fitted tonight using 'Task Master' (brand) of screw in insert nuts and matching 10mm long M6 cap screws, as seen below... First up I clamped the boards into position and measured up where I wanted to drill 5 holes in each board, of course equally apart. I first drilled a 3mm (1/8") hole through the MDF and base board frame. The hoes in the baseboard frame were then enlarged with a 7.5mm drill bit. I must remember not to purchase high speed bits, they fly through the timber uncontrolled with very little throttle... From the back or inside edge I used a allen key to fit the insert nuts. The facing edge of the nut is 6mm in diameter and the end where you insert the allen key is 8mm in diameter. So for a tighter fit I chose the 7.5mm bit... After getting all 10 insert nuts in and flush with the outer face of the base board frame, I had to open the holes a little more on the MDF back scene boards. I used a 6mm bit for this. Then it was time to fit it altogether... The small cap screws work well as they also have a allen key head on them, making for easy insert as the head diameter is 10mm and they are 5mm deep. So now the next job for tomorrow afternoon/evening is to find the wall paper paste and get the image up onto the boards... Cheers, Gary.