Hi Brian, welcome to the forum.
I think I'm right in saying that the Chartwells are the most desirable of the LS3/5A variants so you won't have much trouble selling them.
Ebay will, I'm afraid, get you the best price. But only sell for cash on collection as eBay gives sellers no protection against scammers. Also fees will be high.
Other options are to sell them on a hi-fi forum such as this one, they will realise less but there is much less chance of being mucked about. Or sell them to a dealer, again you will not get top dollar as the dealer has to wet his beak but the trade off is a hassle free sale.
Current Lash Up:
TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.