It looks like the neck joint is the 17th fret, in 68-69 they moved to a 19th fret neck joint.
Nickel parts were used to about 64-65 and then they went to chrome.
The TD stands for thin line and dual pickup, had it of been cherry it would of been a TDC.
So it does look like indeed a 66 maybe 67 model.
Being my favourite guitar and having a non vintage Korean made model (I’m poor)I bought the Epiphone book to learn more about it and also love watching the older videos on YouTube of Norman’s Rare Guitars when Mark Agnesi did it and he has covered numerous of videos on the Casino.
It is a stunning guitar though, I would have no idea on its value and always feel a guitar of this age and quality you couldn’t put a price on it. It all depends on what the guitar means to you what someone is willing to pay for it. If I was rich I would pay you a decent amount for it as being my favourite guitar and the fact I would love a vintage guitar but I’m not rich 😢😥 What would you like to get for it?