I decided that a custom dovetail was needed for this heavy application; one where the dovetail slide bar was literally a perfect friction fit inside the EQ6 Pro dovetail channel and where the bar was thick enough to anchor the substantial steel hoops which would support the 18kg tube weight.
We now had an old LX200 tube complete with cradles and a very sturdy dovetail which would slide into an EQ6 Pro dovetail channel.
It was going to be a very tight fit but, from experiments, it transpired that mounting the EQ6 Pro head almost 10cm to the east of the existing plinth centre would be the optimum situation.
The EQ6 Pro head normally interfaces to the EQ6 Pro tripod via a mating assembly on the tripod top, locked down by a substantial 12mm diameter threaded bar.
The rectangular box features two holes, one for attaching the Epsilon EQ6 Pier Top interface to the top surface of the box and the other to enable the bolt joining it to the plinth extension top plate to be tightened with a box spanner.
With the plinth extension completed the EQ6 Pro equatorial head (minus counterweights) was hefted onto the Epsilon EQ6 Pier Top.
In this case, as the EQ6 Pro (unusually) allows 360[degrees] of RA motion with the tube end permitted to sink well below the counterweight end, I decided it would be best to load the tube first.