Patent Plate Minutiae

[Hugh Barnes]

One of the things that has always disappointed me about the Cabriolet is the repro (silk screen, maybe?) patent plate screwed to the dash. 

   

I've been on the look out for an original replacement for many years and though I had found one the other day, but when i came to it this afternoon and I went to fit is, I found it to be of slightly a different size and with different details of the patents.

   

So I decided to start a thread here to see if we can record some sort of change log of when patent plates changed and from what to what.

I will start off with the two others I have access to, both of which I think are original fitment.

Firstly my 27 Chummy (date of first registration not known) Chassis no 42727

   

And then my RP, date of first reg, April 1933 chassis number 172204

   

Can anyone else add anything in with different versions so if we can find some sort of pattern? Bottom line is I am still on the look out for a replacement orignal for my car and have one, everso slightly different, as a swap...