Further to my previous post, and excellent advice received. I embarked on Davids idea of reverse printing clear transfers on to the back of perspex blanks.
It took a while to find a similar font to that used by Quad originally. The nearest I could find was 'Lato'. So far, so good. I then had to modify the unique 'Quad' logo, which I did using MS Paint.
So the next stage was to try out my efforts. Initial experiments printing reverse graphic transfers on some scrap acrylic sheet worked very well. After this things did not work out so well!
I had to mark out and cut the 2mm perspex sheet. To get a perfectly square piece with nice 2mm radiused corners, and then clean up the edges to look presentable was extremely difficult. It also has to be drilled. Those that have worked on this material know that ideally you should use a specially angled drill bit, and keep the speed low. After much cussing I was not happy with the results.
Time for a different approach. I toyed with the idea of laser engraving, and looked at a few reviews of cheap Chinese laser engravers which can be obtained for under £60 from Banggood, AliExpess etc. I justified the expense in my mind as 'learning a new skill', but really could not see me using it much in the future.
So, on the off chance I contacted a laser engraving service on ebay. Jon, the designer reckoned it would be quite straightforward to cut and engrave to my specifications. He said, in order to keep the costs down "the more work you do, the less I have to do", so I supplied my artwork which he then refined (much better and quicker than me!). Before engraving he sent me a copy of the artwork for final approval.
The company is Sawfish Lasers:
https://sawfishlaser.co.uk/
You can see from his website that they can engrave on to many surfaces, ie wood, metal. He is very friendly and can work from a hand drawing, jpg or a document.
Please see attached, my badges are about 95% accurate to the original, I'm not a purist so that's good enough for me (it won't be an original restoration as I'm fitting IEC sockets etc).
Here's the punchline - I have 4 badges at less than £4 each! I reckon this is an absolute bargain. I have no connection with Sawfish, just a happy customer that found them on a web search.
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Pete