Hi Ian,
Yes the foliage is very similar, and of course this also varies according to what conditions they are grown in eg sun/shade.

Sunray's growth is more upright and bushy compared to Tom West which is more of a lax upright.

Sunray's leaves are light green, edged creamy white, suffused cerise, with a silvery cast. Whereas Tom West is green, cream and cerise, if grown outside will lose much of the cream variation.

Tom West has one or two imitators as both Herbe de Jacques and Old Somerset are considered to be identical, which makes it even more confusing :)

And now the flowers:
Tom West:
Tube small, red.
Sepals short, broad, also red, held well out.
Corolla purple, small and compact.

Sunray:
Tube red, short.
Sepals red on top, deeper shade on the underside, reflexed.
Corolla mauve, small, compact.

All in all, quite confusing. Hope this helps you somewhat - Kath:)

Oh dear! I'm back to thinking it may be Sunray again.
Thank you for such a detailed answer. I've sent a pic for you to have a look at, as I can't 'post' to GW. Hope you don't mind.

IanS