Congratulations! That is a really nice estate find!

You can try listing the box set and other collectibles in the Acaeum Classifieds section, and you will get several offers while managing to avoid eBay fees; however, the largest market is still eBay.

The box set is a 3rd Print Woodgrain as you have identified.  Overall, the box itself is probably in Very Good/Very Good+ condition due to stains on the cover, rubbing on the edges/corners/spine, etc. (It is really difficult to find a box in absolute perfect shape, but they do exist.)  The reference sheets have writing and the booklets appear to each have a bit of staple rust and maybe a little cover wear; the interiors generally look clean.  I would say each of the books are in Very Good+/Very Fine(+/-) on average depending on corners, interior, staple rust, cover wear etc.

The copy of Chainmail is a 3rd Edition, 1st Print and is really hard to find these days; the later printings are much more common.  I would also give it a Very Fine- rating. Value on this one would be much higher $250 - $500+.

As to value, I would guesstimate $3k to $5k+ for the box with the original three volumes and the reference sheets. If the supplements I - V are all first prints $100 to $200+ each is not uncommon, towards the higher side with the earlier supplement numbers.

There is some debate as to whether an auction listing or a High BIN/Best Offer approach will yield more on eBay.

If you have photos of any more items acquired from the sale, we would love to see them.  

Also, beware of low ball offers, and if you have questions, feel free to ask.