Wow, I'm glad to hear that they're swamped with orders. I'll take a delay because of that!
In terms of how to modernize their products to appeal to a larger audience, I think we've talked circles around this subject; they can't design compelling new products because they have limited capacity to do so and the cost of upgrading/changing their manufacturing equipment is so hellaciously high, they can't afford the risk of pumping out a new product that won't sell like gangbusters.
Unicomp's products do not appear to be bad, and compared to other "premium" keyboards, they're reasonably priced. Their primary drawbacks are nonexistent marketing (indeed-- what is their marketing message, aside from relying on people knowing they inherited the legacy of IBM?) and products that are, frankly, dated looking.
But how much really needs to be re-tooled? The basic proportions and layouts of a good standard keyboard don't really change. If you took the guts out of a Customizer, slapped it in a Das Keyboard III-style glossy case, and threw some brighter LEDs and black keys on it (or if black is no-go, perhaps black lettering on a charcoal-grey key for the stealth look-- and then, and this is the important part-- got a few into the hardware press-- they'd sell a boatload of 'em at $90 each.
Hell, take the 122-key layout they sell for terminals, put it on USB, define some of the extra keys for media controls, and ship an app to define the others for macros, call it "Gamer Extreme Samurai-King Keyboard of Dark Evil Powers" or whatever, and charge $120.
None of this requires new technology, or even reworking anything with critical tolerances-- just possibly firmware changes and some new mould-work.