WS 22: Servicing a SEIKO 7005 including replacing the balance

I found three service marks on the inside of the case back. A reason to worry actually, because as you will always read in Rob's service report of the same movement, local watchmakers often work with inexpensive and or inappropriate tools. Not out of bad intention, because good tools from e.g. Bergeon are often too expensive for a small workshop. 17-5-30 translates to 17th May 1987. The case back's first two serials are 43, thus I believe this watch was manufactured in March 1974.
The rotor showed some corrosion yet I was happy to see that the screw slots had been treated respectfully by previous repair persons. The lyre spring of the balance shock protection looked like it had been in an out for many times. And indication for me that someone had infact "played" with the balance a couple of times. This could also explain the not equidistant turns of the hairspring, marked with an orange arrow in the detail below.

Please click on the last picture to read on >>>