Interesting that this thread popped up again. Morris Hallowell recently listed a G&H customized Winchester M61 with 1/4 rib & G&H detachable top mounts on his website www.hallowellco.com.

In general I think the 1/4 rib looks OK but I don't like the way the breech end of the 1/4 rib was handled. At the very least it should terminate flush with the back of the rear scope ring. Blending it into the receiver contour more like what was done with the Simmons ribbed 61 might be an option also.

Anyway, someone spent $$$ on a custom M61.