Thanks for the tips. I'm picking up my angle iron tomorrow 30mm x 30mm x3mm and I'll get some flat bar too as this will do for the mounting tabs and the ring. Did you do mitre cuts or cope the angles? All I have is a grinder here so hopefully I can be accurate enough.
I've bought one of those 45 degree magnetic clamps though so I can just fill any imperfections with weld
I've bought one of those 45 degree magnetic clamps though so I can just fill any imperfections with weld