I can toss in my 2 cents, I suppose.
I highly doubt the interior is pine. Pine is aromatic. A guy would have to be retarded to use pine in a humi. Poplar or birch is fine, it's non-aromatic but it's softwood.
I can see why he laminated the poplar? to the paduak, it's because paduak is CRAZY expensive. Ebony is out of this world expensive.
Because I work with the stuff and buy wood, I'd know it was impossible to build that box of solid paduak for the price you paid. The material alone would be close to that price (if not more) if it was made of solid hardwoods.
Setting in stop hinges takes time, but they're easy. I do it by hand with a chisel. The best corner hinges are side/back or corner stop hinges like this I use 4 screw ones in brass)...
They require tons of setup, lots of time, and are sheer hell to install. It's what you want in a humi, though. If it's a wide solid hardwood humi, the lid will be very heavy and you have to add a couple flat stop hinges (like you got) in addition to corner hinges or screews will tear out and the lid will fall off.
If a guy builds a humidor from solid hardwood and hinges and recessed mating surfaces, it's is 100% impossible to get a 100% water-tight, air-tight seal. I like to mate surfaces and use foam and some sort of positive latch. That way they become zero maintenance. Sometimes it looks good, sometimes not, so I've decided to do things a whole different way. I'm just playing, though, looking for my own design that I'm personally pleased with that I'd be proud to offer to people.
That's not to say that a guy can't get a very good or perfectly usable seal using conventional humi-building techniques, it's just that I personally shoot for 100% airtight so there's almost zero maintenance.
That box is real close to being worth every dime you paid for it. Were the hinges set in, you'd have your money's worth. The guy cut a corner that shouldn't be cut, that's all. I'm sure any customers would pay an extra 20 bucks for the time proper fitment would take. He just made a silly move. It happens.
Handmade quality takes tons of time. The guy didn't do a bad job, not by a longshot.
And the humi is well worth what you paid.
I think you're right in sending it back. I wouldn't accept it in it's present condition, either. Nor would I send one out in that condition (speaking strictly on the hinges).
I can't really assess the quality of the handwork, but it really doesn't look bad in your pics, and the humi has a lot of touches that require extra time. So like I said, it's worth the money right up to where he flunked out on the hinges.
To make a solid hardwood, top-flight, heirloom piece in that size range, you'd be hard-pressed to find something at twice the price. I just mention that to explain the market he's shooting at. I think you deserve and want a little bit better for your money, but you're going to have to spend a little more to get it. Expect to pay $800-$1200 for something around that size, solid hardwood, with medium respect to handwork and fitment and finish.
I hope that helps!!!
Scott