Mounts turned out perfect. CD drive now in place and held solid. Shame I made a bit of a mess cutting out the front panel but perhaps one day I can try and model one and print a replacement.
Fit an ESS 1869F and installed the drivers from vogons drivers alongside phils dos startup pack. This is the same card I had only briefly tested before and it wasnt working great but in this machine and pure dos its perfect.
All working great! with a real 500mb HDD which makes all the right retro noises.
Edit: That gap between FDD and CD is actually like that on the ones with factory fitted CDroms!