What Lionel 3-rail (old style) rail stops are available and where?

The postwar bumper blocks, if that is what you are referring to, are available everywhere. Seems they made a gazillion of them. Google "Lionel #260".

@452 Card posted:

The postwar bumper blocks, if that is what you are referring to, are available everywhere. Seems they made a gazillion of them. Google "Lionel #260".

Depending on condition, they sell for $3-10 each.

Another option is to cut blocks of wood and attach them to the ends of the shelves.  FWIW, I cut grooves in my shelves to hold the cars in place rather than using track.

Not sure how your shelves are configured, but I'd be more concerned about items falling sideways off the tracks.

@452 Card posted:

The postwar bumper blocks, if that is what you are referring to, are available everywhere. Seems they made a gazillion of them. Google "Lionel #260".

Yes, that is exactly what I was looking for.  I thought about cutting grooves in the shelves and decided that I had enough woodworking projects already.  I was trying to simplify the shelving of the cars and locos, without them rolling off.  As far as the other comment regarding falling forward (I think), the shelves are 1" x 6" x various lengths.  I plan to put a 1" x 2" face on each shelf so that if it does come off of the track, it doesn't go far.  And they won't be at the front edge of that 1x6.  More like the middle or so.

Thanks for the ideas.  Scott

There's a cheap option available too: They come (came) 2 in box.  Plastic but they have a light, which I guess won't matter for what you are doing with them.  I don't know the stock # but they are a Lionel product.

- walt