No, Dave you misunderstand, the stirrups are a industry standard, or rather 2 standards. Side and Head. But that type of lamp, steel bowl, ali rims, there are a number of different diameter lamps. The ones I had were apparently smaller than ones Fitted to a Sentinel, so that market wasn't mad interested. Alan Eatwell saw the big picture, the rarity, and the quality of the product and paid full asking price unseen!.
My view with your restoration is that provided you put some period stirrup mounted lamps on it, there isn't many about who know enough to pick holes with it. In anycase the lighting may well have been an option, or indeed purchaser fitted.
The ali rim commercial lamps are actually much rarer than the car equivalents in brass. That said the market is such that despite being rarer they are not that many punters who want to buy them, whearas the easier to find large car equivalents (usually brass bowl, brass rim) are easier to sell, both to the actual large vintage car - market, but also to those making Mk6 Bentleys look like 4 1/2 litre Birkin Jobs.
They are all a much of a muchness price wise. I got over £600 for my pair nearly 10 years ago, but they were ready to fit, reslivered etc.
I notice there is a nice pair of ali rimmed Smiths lamps wanting a bit of work here, and don't look out of the way in price terms.
https://www.prewarcar.com/168967-smiths-headlights-for-a-variety-of-british-cars , but they do appear to be in New Zealand!.