The copper who nicked me for speeding commented on my7x5 said didn't really bother him but some of his colleques would nick me and get it changed, now back on standard just can't be bothered with the grief
If you stick to the regulation size letters and numbers and they will fit on a smaller than normal number plate (I have two 1s on the top line so only takes the space of 3 letters/numbers) and you have the post code and BS on the plate would it be 100% legal??
This was back in the 90s, i was sitting at a set of lights on my winter rat bike minding my own business, when a City of London bike cop pulled up beside me and told me to pull over to the side of the road, he then informed me that he felt the font on my standard sized plate was incorrect, he produced a retractable steel tape measure, and gleefully informed me that the height of the letters and numbers was 5mm to small. I thanked him for telling me and went to ride off, not realising he had gone back to his bike to get his ticket book, he balled me out, and issued a defect ticket giving me 2 weeks to get a new plate and the ticket stamped by an MOT station, which I then had to take to a nominated police station. Got a new plate made up and fitted it and mooched off to my local bike dealer for inspection and stamp on ticket. Guy at shop comes over to me and asks if i am taking the piss, taken aback, I ask what he is on about, when the plate was made, they had transposed 2 letters and I had not noticed, so it was back the makers who admitted their mistake and made another plate, so back to the bike shop, stamped form and off to the nick. All for a poxy 5mm!
Just wished the buggers would be consistent about plates. I'm currently running with a horrible air brake as I can't be bothered with the hassle.