It is a rare pistol since it is in original condition, with original box and, presumably, original mags. It is over 20 years old. It has not been upgraded. To collector like me, this is a prime example to add to the collection. To the other 99.9% of the Glock world, it is just another Glock 19 that happens to be old.
2nd Gen G19s were made for 10 years. 2nd Gen G19s that had black internals were only made for about 2 years.
The question about how much more valuable the Glock is over another G19 is only valid to a collector. I'd be more than happy to send you a brand new G19 in trade for yours if you feel the need to have it upgraded and the like or even buy the black internals.
Bottom line is: yes, it is original and has not been back to Glock for refurb. If it had, the black internals would have been upgraded and discarded. Keep in mind that your pics are bad, so there is a slight possibility that the flash and fouling are making parts look black.
USMCR 1997 - 2004
PAARNG 2011 - Present
Founder - Glock Collectors Club PA Glocker #39
Looking for G22 PE389US
Multiple Armorer Certifications