clamp for 60mm guide scope

[cdh79]

So, i have this Orion 60mm guidescope that comes with guider-rings with 3 adjustable screws.

I would like to replace these rings with either a clamp or proper rings, however I can't seem to find any that fit.

I measured the circumference of the guider being 21cm, which equals to a diameter of about 66,85mm, however most small rings that fit 60mm scopes are 85mm ID, so much too big.

 

One option is to buy the bigger rings and then place a much thicker felt inside, however before doing this, I wanted to ask how other people with similar sized guide scopes have solved this?

 

thanks,

Chris