Timing Gears + & - Markings

[Winston Teague]

Hi all, we are well and truly stuck into rebuilding an early coil bottom end. It has a 1 5/16 crank (without the oh-so-useful cutaway notches for knocking out the main bearings). The timing gears are both badly chipped and unserviceable. They are not marked with a mesh correction +/- figure and neither is the crankcase. I suspect that all the bits are original to the case ( the crank and flywheel are numbers matching). Does it pre-date meshing figures or does it mean that it is, in effect, +/- 0.00 thou?
If the latter does anyone have a good pair of zero gears available please?

All the best, Winston & Patrick Teague