dozens of old .049 TeeDee's, Medallions and a few others

I would sell each one in "as found" condition.  Personally, that's the way that I buy them.

Amateur "cleanings" usually do more harm than good.  Not knowing your skills, model engines are most at risk two ways, when in flight and when a rookie get's his/her hands on one with an oversized screwdriver in one hand and a set of pliers in the other.

balogh- Yes, the .09 is a Medallion, my mistake. I would be happy to pass along any of the "parts" engines to fellow members at a fair price.

rsv1- You make a good point. I need to be careful and "first do no harm". I am a handyman of a sort, but I haven't opened a glow engine in more than 50 years. And don't know if any of the ones I dismantled as a teenager survived the surgery. I will educate myself first, then cleanup and lubricate a few of the less valuable ones where I may make some mistakes. And finally, I'll start and chose the best of them to keep. These are all used engines, many of them modified. None of them appear to me to be in collectable condition.

I'm not only interested in selling some of the engines. I plan on using just a few for flying 1/2A models. I am interested in everything about Cox engines, just as many of you are. CL flying and glow engines were a big part of my childhood. And now I enjoy spending some of my retirement time pursuing interests and re-living experiences from my youth. So no, I don't want to just sell them as is.

As I look around this site, I can see way more information and many posts that are beyond my understanding or interest, I am a newbie to most of this. But this site is a treasure trove of information, a valuable resource for me, and I expect some of the members will be interested to hear about my exploits. Right now, I'm trying to learn how to identify a thin wall, stepped cylinder that balogh recommends.

figure out which ones you want to keep.
keep 2 or 3 more like it for parts

get your paypal ready and spend lots of money with our 2 sponsors:
https://coxengines.ca
http://www.exmodelengines.com
they will have many of the parts you need.

Don't monkey with the motors till you read more, have right tools, etc.
you dont want to damage the motors, and then have nice paperweights

once you figure out what you want to keep?
Figure out what you want to sell.
this is a good place to sell, or, of course, fleBay is for maximum profit.

you have some nice ones. and? like me, you may sell of stuff, make $50, then 2 years later, which you had kept them all.
(can not believe I sold a metal "spook" endplate)

there's lots of fellers here who can give you great advice.
i say? get em flying

Hey robme, here is the.link to cylinder identification, but you will find the link on the left side of thus page direct

https://www.coxengineforum.com/h23-cylinder-identification

Thank you all for the good advice.
I have to clear my shop of some dusty woodworking projects before I have a clean space to work on these engines. So, there will be no progress reports for a little while.
There are a large number of posts on Youtube. Does anyone have a favorite Yuotube channel for engine repair demonstrations?
Bob

here is one and you can ck search engines https://www.coxengineforum.com/search?search_keywords=cleaning+

If you're serious about not using the throttle... I would be interested in it.
PM sent.
CT

Thank you, Eric and others. I've learned a lot about cylinder walls and engine cleaning. And I'm feeling more confident about restoring these.
I got a delivery of 1/2A fuel and a battery clip from Brodak. I found that no one sells the old style 1 1/2v hobby batteries like I used in the 70's. Thank heavens for Brodak and the few other hobby stores that still exist. Where would we be without them?
I haven't touched the fuel yet, but I did test the glow heads on the engines shown above. To my surprise, most of them were good. I didn't count, but it was about 75% that fired up. One head blew a puff of smoke and died.

So no, I don't want to just sell them as is.

Well good, you learn re-learn by doing. Nothing like a hands-on experience. Heat is usually your best friend when dis-assembling. Pliers are a no-no. Use the proper tools, a good fitting screwdriver is a necessity.

I buy used engines, by the hundreds over the years. The worst beat-up engines that I could find, but in my old age I have modified that a bit. Do a little research. It's just a lot of fun cleaning these engines up and restoring them to usable function.

Bob