If your LHS doesn't have it, you can order it direct - perhaps a bit late for now
http://www.bytownrailwaysociety.ca/sales.htm
Smiths Falls Railway Museum, Smiths Falls, ON
http://www.sfrmeo.ca
Canada Science & Technology Museum, Ottawa, ON. You can also see Bytown Railway Society's equipment at the CSTM,
Lots of places in Northern Ontario where there are one-of-kind artifacts. For example, Chapleau, ON a 2-8-2 Mikado. White River, a division point on the CP Rail trans-Canada line.
The Western Development Museums in the Prairie Provinces usually have artifacts. Again the Canadian Trackside Guide will list these items, city-by-city within each Province starting in BC and going eastwards to Newfoundland & Labrador.
When travelling through the Rockies, try to spend the night in Field BC (30 km west of Lake Louise). Camping right in Field, B&Bs, Kicking Horse Lodge, reasonable prices for the area. This is the most spectacular railfanning territory in North America. In the 30 km between Lake Louise and Field, CP Rail trains climb an extra 600' and then drop 1,200' in 6 miles through 2 spiral tunnels, a rock avalanche shed, and a bunch of smaller tunnels. The territory between Field and Golden BC is also spectacular with the CP line running right alongside the rushing Kicking Horse river. West of Golden is the start of the Selkirks and the infamous Roger's Pass. Take a bit of time to cruise the yards at Golden as the coal trains come up the Columbia River valley to go to Vancouver. You can see the railway line across the valley to the summit as the trains snake across a narrow ledge up to the summit. Two tunnels go through the mountain. Stop at the visitor centre at Glacier and take a look at the model of the tunnels. Then take a walk on the original roadbed over the pass.
As you descend on the west side, keep your eyes open for the entrance to the new McDonald tunnel. Keep an eye open for the railway line as it roller-coasters down the Illacilawet River down into Revelstoke. At Revelstoke, stop in at the Revelstoke Railway Museum. It's well worth the stop.
I could go on and on and on, but this would take up a lot of time. I'm sure you'll get some input from other folks. But first and foremost, pick up the Canadian Trackside Guide. Give Hobby Junction a call. Perhaps ExpoRail in St Constant has a copy. Or stop in at Larkspur Line in Merrickville. It's one of those "don't-leave-home-without-it" items.
Enjoy your trip. (I know you will!)
Bob M.