Brownells offers a Picatinny rail set up made by Near Manufacturing- it is extraordinarily expensive in my opinion- Part #100-000-833.

You might direct your questions to the gunsmiths on the website in their tech department.

If this helps...

I found these on Steve Wagner's website. They're B-Sqaure bases for M98's.





If you have a regular M98 and want to use the B-Square base, you may want to leave the charger hump there and use one of these?

http://www.kenfarrell.com