Weaver Bases for Marlin 917M2?

[CyaN1de]

Anyone know which Weaver Base model fits on the Marlin 917's with Heavy Barrel (.820 I believe)? weaver-mounts.com does not list a part number, only a side note which reads

> 900 Series in .17 & .22 Calibers - (Side Note) 12

12. Rifle has Grooved Receiver for Tip-Off Rings.

I would rather put weaver style bases and rings on, so, anyone in the know?