I'm glad you found the images to be of use. The 'options' page shows that pre - WW2 buyers had several factory installed options available to them across model lines. In other words a sight that may initially seem 'improper' may well have been available as a factory installed 'cost option' when new. Surely images of Mauser, ZUM, and other European catalogs and advertisements of the day would provide more examples.

Regarding your type B sight/ military/ sleeve/ modification question, I don't know.
I have but cursory knowledge of Mausers, member Kuduae would likely be an excellent source of accurate information on the topic. Hopefully he'll 'weigh in'.

For highly detailed, high resolution photos that will enlarge well, look through Dorleac's archives and / or contact (member) Joel Dorleac. He is an expert restorer of Continental firearms and certainly knows his stuff.

My 1924 proofed Mannlicher Schoenauer M1910 Take Down (yes, I know, it's Austrian) wears a factory installed 'pop up' tang sight of the type that was also available (factory installed?) on Mausers:

I'd love to get hold of a Sportarget. Watch Ebay and other auction listings for Lyman 35.

Lyman 35 parts: Ebay 35 parts

Sportarget with different mount: Ebay Sportarget

Pricey Lyman 35: Pricey

This looks like the model Kuduae modified in his thread: PH Sportarget

Did you notice the "half round, half octagon barrel with raised matted solid rib" on the Model 610 image?
"Supplied regularly only in caliber .30 - 06 U.S. but can be had on special order in any Mauser caliber."

Parker Hale Sportarget on Mannlicher Schoenauer: