Distinguished SOTW Member
The changeover of font size happened whilst Geoff was still making them. It is a reasonable indication of when they were made (bigger font more recent) but not reliable for distinguishing Geoff from Jason.I think the geoff lawton pieces have the words and letters in a small font, and the newer jason lawton pieces use a large font.
As far as I know, having spoken a few years ago to Jason, the production since Geoff's death in October 2003 is only of the standard models (B, BB and no chamber marker) and so doesn't include experiemental or unusual models like the ICON, the Long Window (LW), the Reflector Baffle (BR and BBR) etc. Also I haven't seen any Stainless Steel models made by Jason, but don't know for sure whether there are any.