My turn!
It's a Jeagers. No doubt about it. We have several of them. I grew up using a six inch Jeagers. The old man and mom would go to many public events and set it up for viewing. The color issue is way overblown. Yes, things have improved and yes, you can get filter to help. However, it's not really that much of an issue. Although, on really bright objects, such as Sirius or Vega it can be one but, how often does anyone look at those as a main object? Really?!
The focuser is also from Jeagers. We have at least one laying around here somewhere. They are actually decent focusing units. When cleaned, lubricated and adjusted properly they can do very well.
I will be very interested in seeing what mount comes with it. I'd jump all over that trade if it were local and offered to us and I have a sand cast C-8 sitting right behind me. It's not been outside in four years mostly because New Hampshire has such horrible weather and the old man can't drive at night because of cataracts. Of course, free time is also required and never seems to coordinate with the weather. It must be a government conspiracy or something. LOL
Those lenses went out of production in the mid 1970s, I believe. Since they were almost identical throughout their production run there is no way to really date them. At least, not of which we are aware. We know when two of ours were made because we bought them from the original owners. One was 1965 and the other was 1967. We also have a 1910 Mogey 6 inch f/15 but, that's a horse of a different color. LOL
I can tell you that these are wonderful telescopes for deep sky work. We have seen the central star in M-57 multiple times with our 6" f/15 Jeager as well as with our 4" f/15 Jeagers. Using the 6" Jeagers the old man and one of his friends managed to score the Horsehead Nebula once. It was on a brutally cold night with no Moon, in a very dark area of the state, no lights anywhere at all, a big blanket to shield them from every other source of photons plus, lots and lots of patience. From what they told me it was the observing challenge of their lives.
So, you have a change to get a really fine instrument which will wow people much more than that old C-8. One of the best parts about a big refractor is the WOW! factor when people see them. It is what people expect when they come to public events and time after time people would line up at our refractors and ignore larger reflectors for that very reason. Yeah. That was fun!
Take the trade! You won't be sorry!
Q