Not a Malcom, but I have quite a bit of experience with the tasco.
I did not like the adjustments and base set up on mine, so I had me tool and die buddy build me a set .
He made three, but I think they are all gone.
Here's some pics.
This is a a 40/65 Uberti BTW, and my buddy here is shooting it at 400 yards across the river at a 1 foot square rock - yup, he hit it!
The mounts are fully adjustable, and lock up as well.
I sold a set of the mounts to a guy who put them on a malcom BTW, and he was VERY pleased with them.