It was quite common for many years to use a single front bolt-on Resilion cantilever when riding a track bike on the road. No need for fork crown drillings. This had the added advantage that you could ride with either HP's (pressures) or sprints (tubs). Simply adjust the clamp-on shoes up and down the forks. This is why a lot of track bikes have chrome front forks to get over the problem of spoiling the paint enamel. I use to ride a road/path with a fork crown drilling coupled with a brake lever with an external clamp. I then lived 12 miles from Welwyn (Gosling Stadium) track. I use to put my sprints in sprint wheel carriers and ride to the track unbolt the front brake and lever together change to sprints and hey presto ready to race. In our club we use to race at these tracks. Welwyn, Herne Hill, Paddington Rec, Wolverton and Wickstead Park. Cycled to them all. The late Dick Swann told me that when he worked at Hetchins and Macleans that the majority of the output of frames from the these two companies were track or road/path bikes. Where are they all now?
Best wishes and be lucky. Michael Butler Huntingdon UK.