After watching a YT vid on custom edge connectors, I took the easy way out and had a chat with the folk at a local pcb spot.I use a program called ZenitPCB, (which is freeware, and does read / produce Gerber files).
Most of the freeware should be able to do what you want tho' if you use one of their their edge connector templates, and then tweak the sizing
I explained what formats I had and what I wanted and he said I should send a pdf file which was easy enough to do, just hit up an online dxf to pdf converter.
When I received the quote, it was a bit of a shocker to say the least, R2087 , being R350 for 1 layer setup and R300 a pop for the boards, minimum of 5.
Guess Im going to have to try lasering some aluminium tape to see if its viable.