Tough crowd. If i'd just posted a photo of the crank and said "does anyone know what this is and what I could replace it with" i'd probably get a dozen replies, the first half of which would be "what a n00b, you need to tell us xxx about your system to answer" and the second half would be correcting spelling mistakes in the first half. I try to answer all questions up front, and people won't read it because it's too long? Yeesh.
Thanks for the feedback though. The Vuelta's looked too good to be true.
I didn't know that 144 BCD is the most common track size. I'll file that away for next time.
FYI -
SRAM S300 is a two-ring hub according to the manufacturer. SRAM doesn't show it on their site, but it appears that there's an S300 1.1 (or sometimes called S300 Courier) for sale as well, i've seen both names on various vendors' websites. I'd about decided that an S300 would make sense, until I came across the Vuelta.