Originally Posted by TejanoTrackie

The cog threading on old Italian track hubs is 35mm x 24 TPI, which is 1.378" x 24 TPI. The typical modern English threaded track cog is 1.370" x 24 TPI. So, the thread pitch is the same, but the diameter is slightly larger, which will make for a tight fit. You are probably OK to do this without the risk of serious damage to the hub threads, but make sure to use anti-seize compound on the threads.