I think i have asked some time ago, i don't remember if here or on another forum, with no answers.
Today i have found the same item on Ebay (# 290705926948), with somewhat different aesthetic.
Both have the same elongated barrel, but the lens on Ebay has a more modern engraving style, and the mark which identifies the optics made for british army/aviation.
Mine is quite similar, the only difference being the Dallmeyer logo, which is made in what i think should be the old fashion, with nice, rounded lettering. I think i have seen some pictures of pre-WWII Dallmeyers with the same engravings, so i guess my lens predates the other one.
I purchased the lens out of curiosity, cause there are very few pre-war/wartime anastigmats with a speed of f/8.
My guess was that it could have been a repro lens, but i found no clues on the Vademecum.
The only lens with similar shape, focal and speed, is a late RR adjusted for graphic art work, made in the USA (Gundlach?) and inscribed with the name of the graphic art camera it fitted (Tacope, Tapo... well, something like that ).
When i got my lens, i couldn't check how it's made: the cells were blocked, i applied some penetrating oil, and then... i didn't touch it anymore.
After seeing the same lens on sale, i thought that probably it's not so rare, and that some Dallmeyer expert/collector could be of some help.
I'd be happy to get any info, i tried to find something on the Web, with no success. There is a lot of material about Dallmeyer optics, but this lens is totally ignored.
BTW, i have Rareac f/1.9 lens on Compur No.1, engraved "Shackman". I have seen such lenses being sold for very good money, and even more expensive are the similar SuperSix ones. Why they are so desiderable? And what's the use, given their scarce coverage? If they are used for digital movies, aren't there a lot of japanese lenses which are as fast, more recent, and a lot cheaper?