The National Archives of Australia
www.naa.gov.au has a large number of "Test Instructions" for carrier tracks (amongst other things).
Under "record search" on their website type in "carrier tracks".
A few examples of the instruction titles that they have are;
Test Instruction No 73 - Test No M144-145 - 1 set carrier tracks and sprockets from Eastern Command (partly used)
Test Instruction No 273 - Test No M381 - 1 No set of new carrier tracks (same make), 1 No set of new carrier sprockets [includes one bound copy of report]
Test Instruction No 218 - Test Nos M316-325 - Carrier tracks of five different makes [includes 1 bound copy of report]
Test Instruction No 158 - Test No M274 - Carrier tracks ex Keach Castings
Test Instruction No 2 - Test No 3 - [MG] carrier tracks ex McKay Massey Harris
I would hazard a guess that the track specs would be in one of these reports somewhere.
All these records are kept in Melbourne so if anyone there can spare some time to duck into the archives and trawl through what will probably be pages and pages of useless information they may eventually stumble upon the track recipe...
Ian