Cheap Vixen style dovetail to fit Porta II needed

[digital_davem]

Hi

I have just received a Porta II mount to replace my camera tripod. 

My telescope is currently mounted using an arca-swiss camera mounting bar/clamp which I need to replace with a Vixen/Synta style dovetail.

There are many, many variations available online at all sorts of (often ridiculously expensive) prices. There are some cheap one too like the skywatcher ones.  I've not seen one of these  before so I'm wondering how they attach to the tube rings.  I'm using Canon lens tripod rings with mounting feet like this

rather than traditional tube rings, so the dovetail will have to bolt to each foot using 1/4" whitworth standard camera tripod bolts. Obviously the dovetail will need holes in and I'll need suitable bolts.

Where to start...

[Ruud]

I use one by ADM to fit my refractor to a Porta II, but Celestron males one that costs less and looks better:

€59

It's called the "celestron-universele-montage-plaat.-vixen-style.-30". €20 cheaper than the ADM. I expect that like the ADM there are recessed slits and holes at the bottom for the heads of the bolts you'll want to use.