In late 60's in Japan, there was only one company made decent alloy brake sets. I think they were call Yosigai Metal Works. They had exact copy of Swiss made Weinnman C/P and S/P calipers and various levers. They had 999 numbers on their products and Suntour (namely Maeda Metal Works) had 888 numbers on theirs. Shimano had 333 numbers. I do not know what these triple numbers means but you will see those time to time when you find old parts.
DIA- Compe is original products from Yoshigai's Weinnman (licenced copy) works in 60's, but I am not very sure about it. I left Japan Dec. of 1971.
For my 2 Japanese YEN.
KEN TODA, cool-beautiful North Carolina, USA