For the 'stoplight', it is a Miller's Replica, you can find it at
www.motocycle.co.uk in their online catalogue, under 'taillights'
For the MGA taillight and the dual indicator-cum-sidelamp, it's
www.holden.co.uk, which is the parent company to 'motocycle' and has a link to it.
If you explore their catalogues, you'll see what 'British motoring' is all about - they are extremely fond of the days from the '30s to the '60s, much more than we'd think. You can find headlights with built-in ammeters, mirrors to clip in the end of the handlebars, miniature instruments and mechanical gauges (copper capillaries instead of copper wires) 8)
No, I do not worlk for them, but I really really think they have an absolutely SUPER line of items!

I'm looking at the 2.5" tacho by Smiths, almost 100$ new shipped, but it's the original item from the original '60s...

Again, I apologize for the super size, why is it that it comes 4 times the size ?
Maurizio