Rivets: From time to time, we discuss rivet presses and the Brakeman's Riveter tool on this board. But having the tools is only half the effort. Finding suitable rivets and eyelets for repairing trains can be a challange.
Most of the rivets that Lionel used are called "semi-tubular rivets". While standard rivets are solid, semi-tubular rivets are hollow at the tip. The rivet is set by flaring out the tip and rolling it over, generally with a "rolling clincher". There are hand held rolling clinchers, press mounted clinchers, and the Brakeman's Riveter tool.
I built up my supply of rivets and eyelets by purchasing extras any time I needed a specific piece, and by purchasing an assortment or too.
Some local hardware stores carry a limited selection of semi- tubular rivets. I've purchased some there. For example, I could not find the rivet that holds the collector arms on a 1055 pilot truck on anyone's parts list, but the hardware store had a size that works OK (slightly short).
Hobby Horse used to offer an assortment of rivets. I may have missed it, but I do not see it on their web site. I guess you could contact them to see whether they are still available.
Dr. Tinker offers 12 different assortments of screws, rivets, and springs. While I consider Dr. Tinker to be an excellent parts dealer, I have not purchased any of his assortments.
Dr. Tinker worked for the original Lionel Corp. He has some interesting material on his web site that is worth a read.
http://hobbyhorseproducts.com/
http://www.drtinkertrains.com/