Are you sure it's actually an LB-100 they sent you?
Seriously, once you plug it in, there's just no universe in existence in which an LB-100 can sound almost exactly like an L2000.... So somethin' aint right, but I have a suspicion it might not be just the bass....
Let me explain: first impressions are the worst impressions on any unfamiliar bass. In the first day, about all you can really and truly conclude about a new bass is if something isn't busted or defective, Is a fret missing, is there a speed hump in the middle of the board, do the knobs work, does it make any sound at all when I plug it in, are any of the screws missing or stripped, just how bad is the factory/dealer setup, can I push the strings down on the first fret at all without breaking my arm...
And so on. I'm being a little facetious, but the point is the first day when you first take the bass out of the case is the point where you're the furthest from really knowing if it's a bass you really want that makes the tones you really need. You can only get a ballpark assessment at first.
For example, my Tony Franklin when I first got it didn't sound even remotely, "to me", like a Precision bass. Even though it said "Fender Precision bass" on the headstock and it looked like a P bass, it just sounded totally alien and not like a P bass. In fact, it took about a month for me to acclimate to it and get it setup, kill the zingy roundwound strings on it, and start learning to pluck over the split-P pickup to get anything that I thought sounded to me like a P bass tone out of it.
You can get in the ballpark on the first day or two, but to really nail if it's going to suit you takes a lot longer than that. And even some work on it with tools too, I'm referring here to the setup and evaluating/fixing any defects, etc.
My goal is just to save you some money - I see guys flipping basses and losing tons of money all the time because of "gut feelings" on the first day they take a new, unfamiliar bass out of the case. The action is a mile high and so is the nut, the fingerboard looks like a banana and the pickups are a mile below the strings, which are brand new and brighter and shimmery-er than an old Polaroid flash bulb. An hour later, their arm is broken from trying to mash the strings down and their ears are ringing from trying eke out a good sound from their 800 watt amp and they go "we just didn't click" or "it's just not the bass for me" and it goes up for sale.
Again I'm only exaggerating to make the point

. I'm just saying don't be that guy. Note lots of smileys here

. Or at least, don't throw it away quite yet. It may yet be a perfectly good bass for your needs and you may not have to lose any more money trying to flip it if you work with it a while.
As for the strings, they probably are EXL 170's - that's what's on my new L2000 - and they sound awful when new. Zingy, clangy and stringy and no pop or thump. You have to kill them with a ton of playing before they start to give you an actual note that doesn't sound like it has 100 tons of chorus on top of it.
Anyway, I'd say get it setup first, then give it, say maybe a week of playing time. If you don't start to hear some Precision bass after that, then go ahead and try something else...
My .02,
L