Nice speakers, which look very similar to a Rogers Export Monitor which used a similar transformer crossover.
But instead of the pressed steel Dalesford driver, these cast alloy bass drivers look near identical to the unit used in the later Rogers Studio 1. Given that Rogers bought Chartwell and Swisstone is the company who owned the Rogers name, tjese may well be what was fitted originally. If not they are certainly superior to the Dalesford unit.
These are as close as you will get to a set of Rogers LS3/6. I have heard the export monitor, studio 1 and Graham Audio 3/6 within 24 hours and the differences were trivial