The original looks like this:
And the Compact Tactical looks like this:
I was able to get a factory threaded barrel (with o-ring) from Adam Webber at HKParts.net. The raised sights were a bit more difficult to track down. Here's what I've since learned:
Initially, the raised sights found on HK Compact Tactical pistols came from Novak, although that partnership (if it should be called that) has since changed. In an e-mail (September 20, 2010), Novak confirmed they "still have a few sets left," but there was no answer as to whether those sights were Trijicon and, if so, what year they were manufactured. Manufacture-year will matter because tritium sights diminish over time.
Everywhere I looked on the Internet, raised sights—whether from Trijicon or others—were simply not available for the USP Compact models. It's easy to find raised sights for the full-size USPs, but that's obviously no help in this case.
So I queried HK customer service and was given (what are supposed to be) Compact Tactical-specific part numbers for front and rear raised sights along with a telephone contact for commercial sales. So far I have not been able to reach that commercial sales contact, but I have been able to leave a message describing who I am and why I'm calling; alas, I continue to await call-back. [**update below]
I also added the (significantly underpowered) M2 tactical light, which looked like this:
It's authentic insofar as the M2 packaging is HK-specific (ie, HK-branded) and the light itself fits the HK rail. But the M2 lumen output is just child's play compared with Surefire's X300 and X400, so I've since added the GGG rail adapter:
By doing so, I've permanently antiquated my M2 but can't yet bring myself to sell it. Additional updates to come.
[**Received call and sales rep was extremely helpful. In short, HK is able and willing to install new Compact Tactical sights and zero them; they only need the slide to do this; total price is less than that quoted by Novak.]
