HW/Weihrauch Aperture disks...

[specie]

Here's diopters from the early mid '50's, (maybe a second pattern Weihrauch version?), and from the mid '50's to modern times. Note how the disks get smaller, and less sophisticated with time: the knurling on rim changes, disk gets smaller, cross hatching to decrease glare changes or is deleted (I guess rubber hoods become common?).
I've seen schützen rifles from 19th century where the disk is has even larger diameter...
Yup, really trivia here!

 

[crowski]

Wow. Small world, wouldn’t want to paint it. I just came up from my shop and installed a new aperture on a 601.
I’m fascinated by these sights.

I love how on the your older models they use the stock for stability. Thanks for showing. Crow

 

[specie]

I believe that FWB 601 diopter is somewhat rare, but here's is a Karl Kenyon modified Anschutz 6702 diopter that's similar, for prone shooting?
Here's old pics of an early Weihrauch diopter, early '50's with even more oversized disk, and the Falke copy (?) with a really neat adjustable iris feature?

 

[jkingrph]

No expert, but just looking back on the internet, the FWB 601 rear sight looks a lot like a shortened(front to back)version of the sight on my FWB300s I have a newer 602 and it is a more modern looking sight plastic cover/shroud on the front of the sight which I guess helps to mitigate glare.
Most of my guns wear old Anschutz diopters, with Gehmann adjustable Iris installed. basically the 510, and a couple with 1.5x diopters, and one with color filters. One little gun a HW30 has a Williams sight with a Gehman 502 iris installed, it is the "mini" model a much smaller diameter than the larger 510, leaving a more sporter look on the gun.