Leviset

I’m returning to Astronomy after a long absence. I’ve been given a vintage 1950s Brockhurst & Clarkson (originally now Telescope House) 3½ inch, much altered Refractor on a tabletop EQ Mount - the 2 Perspex 6” setting circles (RA & DEC) are disintegrating. I have a SynScan AZ GOTO Mount. The refractor is held on to the EQ Mount by 2 large Jubilee Clips. I’ve been looking for some kind of adaptor or alternative way to take the refractor off the old EQ Mount and attach it to the dovetail on the SynScan AZ. would this ADM adaptor used here do the trick - how much are they please? I’ve attached 2 images to try and show what I want to do. Am I right in thinking there is a 5Kg weight limit for Mount? Thanks Dennis