Help with 70s C&TS dates

I've been having some fun lately going through a bunch of my 70s RR slides. As I mentioned to someone recently, the equipment was modest and the photographer's skills even more so back then, but there're still some great memories captured on these bits of transparency film.
Which leads me to the request for help. Time, several house moves and other life changes have long since claimed my photographer's notes on most of these (nevermind what's happening to my memory these days), and I'd like to lock in a bit tighter on dates for a couple of the events I shot - three of them in particular.
Here's what I (think I) remember.
Event one: In 1977, the NMRA held its national convention in Denver. Following the convention, there was a trip on the C&TS consisting of rider-boxes (and a stock car) cut out on one side only, intact on the other. The run also used "caboose" 05635.
Event two: following this special, there was a photo freight (the first Peter's freight?) which used some of the same consist for participants from Cumbres eastbound, the cars having been left atop Cumbres the previous day.
From a combination of my memory and the dates on the slides, these events would've been June or July of '77. Does anybody know more specifically?
Event three: In the winter of '77/'78, the C&TS ran a rotary special. A freshly shopped OY plowed nice, deep, fresh snow from Chama to about the top of the narrows. There were also plow runs made with the Jordan spreader.
Again, from slide dates and rapidly fading memory, I'd put this as Jan or early Feb of '78, but if anybody can help me nail this down further, I'd much appreciate it.
Thanks in advance,
Scott