External HDD doing something odd - Fail or can I recover?

Your local repair shop is not capable of recovering data from a crashed hard drive. That's a job for specialists such as DriveSavers, and it will cost a lot more than $250.

I'd be very surprised if Tekserve had the equipment and skill to disassemble a sealed drive under clean-room conditions and install the platters in another mechanism. That's what DriveSavers does. I doubt that you'll be able to recover anything otherwise.

So the fact that depending on which interface I'm using, it gives me different numbers - does that help in the idea department

It helps me a lot. Any drive that cannot provide both its Make&Model and an accurate non-zero capacity/size cannot be initilaized or repaired by any software means.

Your drive has serious problems, and the only way to get more than a tiny bit of data off it is the extremely expensive way Linc Davis has described. Tekserve is probably going to run Norton Utilities on it. They will get nowhere.

Seriously consider re-creating that data through other means -- the data may never come back regardless of how much you spend.

Considering that this is an external drive, there's a chance that the enclosure has failed, rather than the drive mechanism inside. In that case, you might be able to rescue the data yourself by removing the mechanism from the enclosure and installing it in another one, or a drive dock. You have nothing to lose by trying. Just make sure you don't write anything to the drive.