Tom,
According to Hayes Hendricks site,
http://www.midcontinent.org/rollingstock/CandS/dsp-passenger/up-dlg_locator.htm, baggage cars in this period were numbered 1000-1002 (former DSP&P 40, 41, and 45, later C&S 102-104 and 1 and 2) and baggage-mail-express cars were numbered 1300-1302. I don't see any mention of any passenger cars numbered 264 or 383. Ever.
During this period car 64 was a coach (later C&S 77). There is also no 83 circa 1887. I also checked the excursion cars, and none of them appear to have numbers in this range?
Ken, what say you?
Keith Hayes
Leadville in Sn3