The hole spacing is 1/2" so it's a matter of finding bases with that hole spacing AND the proper contour. I first went with two piece bases made for Knight round tops but had problems with positioning the scope as desired.
But I was lucky to discover that 2 front bases for White 97 would fit and give me good positioning options. Those are not readily available though.
What is available are Knight's own round top two piece bases (basically Weaver 45 or S45) or other brands stated to fit the Knight round tops.
If you could contact Skullmount on one of the several forums he visits - he can probably fix you up with some altered Weaver Grand Slam S-452 bases. These fit the contour but the hole spacing is incorrect so a second hole is added. I will pm you his email addy.
The base on the left is unmodified, the right one has the additional hole drilled. Skullmount would need to know you need two bases with option 2.