What dimensions approx?

HI Bill

The base board is made from some old kitchen worktop, so it's as deep (ie front to back) as the worktop was (600mm?)

I then grabbed some caps and just set the edge pieces far enough apart that the caps fitted between them.  And then routered the glue drip channel down the middle.

Those edge guides can be moved outwards a bit (it's only 4 screws) if I need to clamp a wider cap at any time, but it should be plenty wide enough for any standard guitar body.

Not sure I'd quite call it beautiful, but thanks Mark!

I found a slight "operational inconvenience" when using it.  To clamp the sides of the cap in place, you need to get the heads of the clamps underneath the board, which was a bit fiddly.

So my board now has inbuilt clamps!

Just drop the bolts out when using with the sanding beam.

... I went and made a jointing board ...

Its beautiful!