I'm in Glasgow, and may be able to help.
Drop me a line, if you like.
Thank you for your response; I take your point that the design is too wide in the beam to be a 'real' sharpie. I'm also reassured by your...
I'm new here, but have lurked for a while.
I wasn't sure which category to put this in, but it's about design, so I stuck it here......