I have a total of seven 66's. Three are four inch -1's. I have been able to find them locally cheaper. The last one purchased was in December. It is in close to the same condition but no box or papers. I paid $550 but spent another $100 to replace the plastic grips.

I have another 4 inch which came with the correct box but no tools. I purchase it a couple of years ago for $750 I believe. I think the $1000 territory would be correct if not a little higher due to the virus. YMMV. Good luck with your sale.