SMC Takumar 135mm f2.5 issues

xjjohnno · Expire: 2011-11-18

A recently bought SMC Takumar 135 f2.5 is in need of a bit of tuning/ repair. It was advertised as having a non working aperture selection ring and worn auto/manual switch, otherwise excellent condition. Extras I've noticed are infinity is reached way too early, like at about 5m on the focus scale meaning the ability to focus closer is absent. Besides fixing the aperture selection I'd like to get the focus scale to better indicate distances. There are also signs of poor reassembly with the front groups of elements screwing out as a whole. Has anyone here done surgery on the said lens with tips and possible diagrams I can work from to turn it into a happily working lens?