Just received a set of these from Australian Recknagel distributor Graeme Spraggon and thought I'd share with other Brnophiles on Nitro Express. Also available through NECG in the USA. Not cheap at $A225 posted, but very high quality.

These are very well made, machined from tough Dural to save weight, windage adjustable and handle 1" or 26mm scope tubes. Finish is black anodised, 4 cap head Allen screws per ring will handle major recoil. Recknagel part no 45026-0563. Also available for 30mm tubes 45030-0563.

Unlike many roll-off mounts for the Brno ZKK, these ones will not interfere with the receiver mounted pop-up peep sight (the reason why so many early ZKK's are missing these vital parts!)

Shown here mounting an older steel tube Schmidt and Bender 6x42mm scope on my ZKK600 in .270.
Its a bit hard to see in the photo, but the lower front base is scalloped out to handle a much larger objective lens size. I'd say these would comfortably handle up to 50mm dia.