Mr. T., John, and Michael — Grateful thanks for your ideas and suggestions.
I discussed your contributions with my OH, Janet, last night, and she asked me how I knew my ashtray wasn't Whitefriars. I explained that the amber seemed rather pale for Whitefriars, and that it should be in the books or on the website. She then asked how many examples of Whitefriars I've found that aren't in the reference works.
After that earbashing I had to admit that my ashtray could be Whitefriars. So I found and unpacked my two examples of Knobbly and compared bottoms. No obvious difference.
Could my ashtray be Whitefriars?
Enlightenment sought.
Bernard C.
