Hi Steven,
Check out the SRR&RL Website and contact Bob Troup. He can give you pointers to the appropriate parties at the SR&RL. Also John Stinchfield, the SR&RL MM, is usually around during the week, although he is busy doing various projects for the museum and probably won't be able to spend a lot of time with you.
SR&RL Museum Website
The other folks who replied have provided some good suggestions. In addition, don't forget to visit the depot in Albion and swing over to the Bridgton Chamber of Commerce to see the B&SR flanger and tank car on display there.
Have a good trip.
Best Regards,
Glenn