+1 on the ease of a fairly effective cleaning of an objective that can be disassembled.
I hope the objective is a good one. I put money on it the Sears is so sweet because it's a royal Astro lens, identifiable by the tiny mark on the name plate. Mine was an essentially perfect objective, I would have loved to have seen interferogram on it. Too long, skinny, and narrow for my taste, it went to an excellent home.
With air-spaced elements, just be very very careful with the spacers as you will need to reuse them of course. a recent thread mentioned the possibility of replacing them with gradated machinists plastic shims.
I haven't hit etched-glass yet but I have had some damaged coatings, a bit unsightly but no noticeable effect on images.
Do the search on cleaning, there are lots of opinions.
I use an old photo forum trick, pond's cold cream, to remove the infection, soap and water, and if necessary acetone if the infection is tenacious. One photo lens did require that. By the large pec pads off Amazon, they won't hurt anything and they're tough to beat for that final swipe to remove lint or dust. I use lint-free microfiber towels made for car washing, from Walmart, the large gray ones, or regular lens cleaning or finishing up with breath fog when cleaning an objective. The Harbor Freight ones leave a lot of lint. I see complaints about their use, but anybody with half a brain would only use fresh towels, not old contaminated ones. They're cheap enough to cut up into squares and use up over a couple of years, but I find the big ones nice for clean objective handling. with a quality lens, I don't care how many I use and decide to throw away, or transition to car use. They have the miraculous ability to wick off oils without rubbing or any solvent other than breath fog. Mostly for eyepieces, or for when you accidentally touch the lens on reassembly . . .
Nothing beats pecpads for a safe resting place as you're working though, the only problem is they are nonabsorbent.
I've never used the cotton pads, but they are classic for safe mirror handling and cleaning.
And don't over tighten the cell retainer when you restore the lenses to their home.
Mark the relative positions and the, believe it or not, relative directionality of the lenses. It is just too easy to flip an element, I bought two used scopes that had happened to.
On that Sears, try putting the mount onto a stable tripod, or use replacement solid legs. I was in the process of making an adapter for mine when I sold it, legs made it completely unusable even though the amount itself seemed decent.
Edited by markb, 22 June 2020 - 01:41 PM.