This is from a supplier of varnish fix lettering for public transport, dating from the 1970s and produced in the UK. This face seems to be used interchangeably with Alternate Gothic no. 3, but it's something different. Struggling to get a positive ID anywhere.

While its origins may have been a commercial typeface, it was likely custom for this specific application.

Barlow Semi Condensed is similar, and was inspired by American transport sans serifs.

Geogrotesque is also very similar, but too rounded to act as a substitute.

39 minutes ago, Kevin Thompson said:

Geogrotesque is also very similar, but too rounded to act as a substitute.

While Geogrotesque Sharp is a bit too square…

I was unaware that Emtype finally released a sharp-edged version of Geogrotesque (just came out last year). Well played, Riccardo.

Thanks all for the replies. I should have clarified that the original I posted is the template from the backing paper of the transfer. To clarify what I meant with it being used interchangeably with Alternate Gothic, here is another item from the same supplier. If you ignore the numerals everything is in Alternate Gothic 3 except for that capital 'G' which seems to be the one in use in the sample at the top. Very odd!