Vintage Red Submariner Questions

[yaqona]

Greetings. My father-in-law just handed me his old Rolex to sell. It is a numbers matching 1680 red submariner. He's the original owner and it was issued to him by civilian organization that was working with the Navy during the Vietnam era. It was not issued by the Navy. It has normal scuffs from wearing it for about six or seven years in the 70s and then it has been in storage ever since. There are a few scuffs to the glass that will need to be buffed out but do not look like they are cracks. The band is not original and was replaced 20 years ago. I have the original box and certificate and manual. I listed it on eBay for $13,000 and by the immediate response I got realized the eBay was not the proper place for a watch like this. I got offers of up to $15,000 but since this is worth way more than we thought I want to sell it to a more legitimate buyer. My questions are where do you recommend selling a watch like this? I have sold on Bonham's before and I am considering that unless you tell me otherwise. Also, does anyone have an idea of what I should expect is a fair price for this watch?