The Winchester orig design on the rifle to tighten up a loose TD is kind of flimsy IMO, for lack of a better word.
Take the forend wood off. Then tighten the 3 small screws on the muzzle side of the Bbl Extension just enough so that they dimple the flat surface on the breech side a little.
Those 3 pushed out metal contact surface points produced by the screws dimpling the metal are what then gives you a tighter TD joint when the frame and bbl assemblies are put back together.
It does 'work', but will quickly get loose again from shooting and using the TD procedure again and again.
Some have been pushed so far out from eachother that the bbl assembly actually sits slightly pointed upwards in it's threaded juncture.
The TD feature seems to be as much a novelty to show off as useful, ast least in these times.
I usually tighten the joint by carefully peening the bbl thread 'V' towards the muzzle. Going around the entire thread with a punch that fits the thread and angle and with careful educated light taps, the thread is swaged forward just a couple .000 at most.
That makes the bbl assembly take-up a bit quicker when screwed together/assembled and it will tighten up as firmly as needed.
Sometimes you will need a vise and wrench to bring it up to 12o'clock.
But then,,leave it there and use it as it is..don't TD it any more.
Admire the Winchester L/A TD feature from arms length.
Swaging the bbl threads can be used to tighten most any bbl that over clocks it's position on a frame/reciever.
I don't know if $800 is a decent price for the rifle or not.
As said,,they seem to be all over the place in values. It's certainly only a shooter in the condition it's in inspite of it's mfg'rd age