I see. Well, maybe the seller just wanted to protect themselves. If it is the real MD-760 (and e.g. they are not sneakily shipping you an MD-750, as the number looks so close.), then it should be compatible. However, I cannot find any verified info that any places online that have actual stock, as there have been a few cases posted here that the seller told the buyer that they couldn't ship them the products as they actually didn't have any (so prob a stale listing on Aliexpress.).
Used GD-77 came up on eBay from time to time, but asking price was higher than when they were new. Nuts.
But now we have an alternative (although still experimental alpha now) w/ the TYT MD-UV380 / Retevis RT3s (and possibly the UV390, not sure yet) OpenMDUV380 firmware development, as these are still vastly available, although the price had gone up since their lowest a few years ago.