I agree. In the single-cut case, my guess would be that Jericho guitars may be successful; though, perhaps not with the Explorer copy, given Gibson’s recent success against Dean.
In 2004, PRS lost a lawsuit brought by Gibson against PRS’s single cut models. That lawsuit stemmed from a cease-and-desist letter issued by Gibson in 2000. But, the 2004 decision was overturned in PRS’s favor the next year.
So, it would appear a single-cut model is now considered generic and nonspecific.
Well, I've done some more digging. This gets interesting (to me anyway...'cuz I'm weird, like that)....
In 1993 Gibson did receive a trademark on the Les Paul shape. Trademarks do not expire, like patents, so it remains in force. When the 2004 lawsuit against PRS was overturned, the basic bottom line of the overruling was that the PRS guitar would never be reasonably confused with a Les Paul. Essentially, Gibson does have a trademark, but PRS did not violate it. There's more to it than that, but that is my summary.
So, whereas Gibson does have a trademark on the specific Les Paul shape, they do not, however, have any claims on the generic single-cut design.
At this point, the question may be raised as to why we see Les Paul style guitars still being built.
Well, because there are no trademark police running around looking for trademark violations. It is up to the trademark holder (in this case, Gibson) to identify and challenge those potential violations. Any builder can make that shape and hope to fly under Gibson's radar or they may think they've made some alteration that will stand up in court. Of course, individual builders may have other reasons, but the mere presence of a rule does not mean someone will not push the envelope of that rule or outright violate it. It may also be that some builders are better luthiers than legal beagles and they just simply aren't aware of Gibson's trademark.
This pretty much leads to the situation we see now.
(Incidentally, I'm reevaluating my thought in my post above that the Jericho Les Paul style guitar may survive a challenge. Given that Gibson actually has a trademark on that particular shape, and the Jericho body shape perfectly mimics it, it seems more possible to me now that they may lose that challenge, too. But, these things are hard to predict. Others have noted that Jericho has pulled that shape from their website. Maybe Jericho is realizing it's a risky battle, too.)