I ended up with a model 66-no dash, 4 inch and a 66-2, 2 1/2 inch, both new in box and unfired. I don't think I'll ever bring myself to shooting them, so am considering selling one or both and would like to know approximate values. Thanks for any help.
If you do searches on the major US gun auction/selling websites for this model and completed listings that sold (not asking prices with no bids), that will give their current real-world values. Depending on whether you are able to ship them to a seller outside your area, local demand may also determine the price. I would guess roughly somewhere in the mid-three digit dollar range, but this is not based on a search as described above.
$700 for a mint like new used 66 with 2.5".... check the major auction site for completed listings..... I've seen new in the box ones with asking prices over $1000......