sekman
Hello and Welcome to the Forum!
Sadly your situation is all too common an occurrence, a train hobbyist passes on leaving the family to deal with the trains.
You are fortunate that an inventory was taken of your Grandfathers Trains and will help with the liquidation.
If you would email me a copy of your list, I'll look over it, do some checking and give you an appraisal and some options for disposal of the trains. 
My email is listed on my profile.

Happy Rails!
Dave