I'm trying to collate the Welsh-made 10-1/2 ligne Streamline/Slimline caliber numbers - if anyone can help, as they are not well recorded.

These were developed in the mid-1960s to replace the 'TY' (0- to 21J) which itself replaced the Ingersoll 5J RY 'Smiths-Empire'. The Streamline ended in 1972. These are readily identified by having the very narrow, independent escape bridge - it carries a calibre number... and states the number of jewels on the barrel bridge (earlier models don't).

The Streamline was designed as a 0-jewel (512 etc) to 17-jewel (627) etc movement with or without shock-protection. 'Jewelled' invariably however means a single (visible) jewel on the balance staff.

The 512 and 522 1-jewel appear identical with shock protection
602 (?) appears to be 7-jewel
627 is 17 jewel

Does anyone know of the other calibres?

Barry