Here is an automatic exposure device for Crowns & Speeds - used with flashbulbs - that changed the aperture as you focused. It was offered in the late '40's. Don't know if any made it to market though. Of course, now auto flash exposure is electronic & TTL and more! Other models were stated to be available for Crowns & Speeds with different lenses. The HCE Company's name is on the brochure which I got from them at the time. I still have the brochure which gives more details and a couple of different photos, one of which shows the whole Speed/Crown with it mounted. HCE also made filters and lenshoods I understand.
To view a photo of the 'focoflash'go to this Web Site -(interesting for other pages as well) http://members.tripod.com/rick_oleson/index-112.html
This "focoflash" photo is a recent addition to his 'Obsolete Technology' section.
If anyone has ever seen a focoflash....or even an Ad...please let me know. They did advertise in Popular Photography in late '40's....where it first came to my attention.