"The unit is now ready for soldering the nickel-silver wires to the switch blades. For this purpose a set of Switch Blade Gauges is used. These determine the correct gap between the switch blade and the stock rail when the switch is reversed.

Clip one switchblade to the stock rail using the Silver clip from the gauge set and solder the wire to the switch blade using solder paint or solder cream. Now, with the Silver clip, clamp the second switch blade to the other stock rail at (A) and insert the Blue gauge in position (B) so that the gap between the stock rail and the heel of the switch blade is correctly set by the centre prong of the gauge, leaving the outer prongs to hold switch blade and stock rail securely. Place the Green gauge in position (C) in the same manner at the toe of the switch blade so that only the tip of the blade is held in the gauge. Solder the second wire to the second switch blade, rotating the wire in the tube as necessary to give a close fit.

Remove gauges and clips and operate the switches, checking that the blades fit snugly against the stock rails. If necessary, the blades should be carefully scraped to improve the mating between stock rail and switch rail. Replace the clips and gauges and, using a fine wire, place a small dab of epoxy resin, e.g. Araldite etc., on the joints of the wires and tubes while the blades are clamped in position."

Notes:-
Blade opening, set by green gauge - C, is 4.25inches or 104mm in standard UK practice
Flangeway at "heel", set by blue gauge - B, is 1.75inches minimum but actual figure and position depends on design of points, it is not usually neccessary to use this gauge as the rail will take up the correct curve naturally.
When making your own gauges there is no need for the 3 prong design, although it is just two normal clips glued together with a shim to give the required 1.5mm or 60thou, you can just use a simple clip and a spacer of 60thou plasticard or brass.
The clips are just hair clips with the prongs cut shorter.

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