Hi,
I have recently bought an SMC M 135/3.5 with minor fungus behind the front element with a view to cleaning it up. I have previously removed, cleaned and replaced the front element on a SMC M 50/1.4, following this guide:
Pentax 50mm f/1.4 strip-down instructions
However, the 135 has proved more of a challenge as the front element doesn't appear to be mounted in the same way as on the 50mm lens. I can remove the front ring (the one with the serial number and 'PENTAX SMC written on) with the aid of a rubber cup, but the mount for the front element doesn't have notches for a lens spanner as on the 50mm lens.
I've trawled several forums and Google, but haven't found anything relevant to this specific lens. It wasn't expensive and I have another (mint) copy, so I'm not too worried about damaging it, but would be very grateful if anybody has any useful advice or could point me in the direction of a useful guide or diagram.
Thanks.