Precision turned Track Gauges are now available from KBscale. Produced in brass with grooves to suit Peco IL-115 code 82 rail. The outer grooves are for setting the 14mm gauge and the inner grooves give a 1mm gap for the check rails as per the published O14 standards.
The gauges have a machined flat at one end to give clearance when used over a turnout crossing (frog).
They cost £4.50 from KBscale (website has online ordering).