I was bored last night working the graveyard shift...
From the partial number plate, and looking at the spacing and known standard font I'm fairly confident that it's one of the following reg numbers:
?004 FDH
?304 IDH
?504 TDH
?604 VDH
?804 YDH
With ? Being the year prefix. If you can work out the year, or at least narrow it down to a few letters you can put the reg numbers into :
https://www.gov.uk/check-vehicle-tax
And see if any come back as a blue Tomos.
I can't tell from the pic, but can you tell if that phone number starts 021 or 0121?
That area code gained an extra number in 1995 so if its 021 that puts it pre '95.
Even things like date marks on tyres can help - if it's got low miles on the odometer and '93 dated tyres, well..
Wish I knew more (anything) about Tomos to help you further
Nedlom