Hi everybody! It's my first post here ( i apologize in advance for how longwinded this is going to be) even though I've lurked around for a bit. I just came into ownership of one of these enlargers and I've got a couple questions for the Durst 138 users/owners (and anyone else who feels like chiming in) that either I haven't seen before or I missed in all my searches. 1) There is a problem with the focus knob for the bellows. It was only able to focus moving down the rod. If I tried to turn the knob to raise the bellows, the knob would just spin freely without moving the bellows unless I pushed up at the same time with my free hand. Figuring it was just some dried gunk causing it to slip i removed the back cover and it seems that over the years the steel of the rod chewed up the aluminum in front of where it sat. Is this anything anyone else has run into? Any ideas on workarounds? This leads to number 2) I may have a line on some later version 138 parts namely the bellows/focusing portion of the head and the upper half of the main stand. Is it possible to mix and match parts from the earlier version with the later? And lastly 3) To those of you who have brought one of these back to life what do you recommend cleaning the old gunk and oil off with, and what would you use to lubricate? Everything moves fairly freely on this one but there is a lot dirt and dried oil/grease everywhere, so I wasn't sure where to apply lubricant and what kind and I didn't screw anything up. Thanks to anyone who wants to help, and this awesome community. You guys an gals have taught me a lot.