See, I replied to myself?Hi, spurlockda.
The service manual DVDs are most likely legit. Like any eBay seller, check out their reviews and so on, to make sure they are a "legit" seller who consistently delivers what they claim to be selling.
Before buying the DVD, make sure it includes all the manuals for your car. If it has a bunch of other Lincolns, but not your year of Town Car, it's a waste of time even if they pay you $10 to take it.
Also, confirm whether this is a "factory printed" DVD or a "home copy." The "home copy" DVD won't last nearly as long as a factory-printed DVD, because home-writable DVDs trade off longevity for being able to be "burned" by a consumer instead of being "printed" in a factory and being unchangeable. This lack of longevity does need to be taken into consideration.
Stand by. That was a lot to digest for an old war horse who spent more time IN the military than as a civilian. We didn't have to use ebay much.
I copy all that you said - I think? If I end up with some Edsel manuals then I'll know I didn't understand as well as I thought