Right then, dusted off the sketchup skills.
The model is of one side of the planer, and shows how a table (yellow) attaches to the 'head' (blue). This is not perfectly to dimension as it's pretty cobbled together.
Hiding the side and top of the table, reveals the upper face of the head. The orange bits are the medal slides that sit in a semicircular channel in the head and table. All the yellow bits are part of the table and are attached by other structures, ribs etc, to the underside of the table.
The table moves up and down by turning the black knob, the knob is on the end of a threaded bar, the red is actually a double lock nut, the bar screws through a brass block (dark blue) that is restricted by the green castle like structure. As the knob and screw are essentially connected to the table, whilst the castle is bolted to the head, any movement in the screw causes the table to slide up and down the slides. The pink part of the mechanism is the lock, the pink bar is on sprung bolts through the head and has a con-rod that goes through the head.
The con-rod has a piece on the other end with a large hole in it, through this hole a bar runs. The bar is basically a long cam and when the locking handle is moved the cam rotates, pulling the con-rod that pulls the pink bar tight down on top of the slides, hence locking the table in place.
View with part of head hidden. Damn! Just realised the slides are bolted to the table not the head, too late to redo the model now, will sort it tomorrow. It's amazing how you realise your errors when you talk a mechanism through and realise it won't work how it's drawn.
In theory you can unbolt the sprung bolts (pink), disconnect the con-rod which should only be finger tight, loosen the locking nut (red) and screw the knob and threaded bar out, you can then lift the tables off.
My problem was that access is dire to the locking nuts on the threaded bar, and the con-rod bolt was rusted tight and i could not work out how to get a spanner on it. So I had to take the whole head and table structure off the base and flip it on its back (two person lift), undo the castle structure, drive out the cam-bar, which gave me the access to the con-rod, free the bolt, I could then pull the whole lot off and get at the locking nuts on the threaded bar.
If you want the sketch-up file let me know and I'll pm it to you once I've corrected the slides bolting to the table not the head.
Regards
Fitz.
PS. All these parts can be seen on the exploded diagram in the Wadkin 9 BFT pdf file, however it's not obvious how it really goes together until you've skinned your knuckles taking it apart. Part 43 is the castle structure, locate that and you'll be able to see how my model and the Wadkin drawing align.