For those of you who like O guage cars and trucks on your layouts and also are careless enough to drop (or more likely...to forget where you put them) I found that the screw that holds the autos to the portion of their original "box" is usually the right size to replace the screws holding the 1130 (& other?) tender bodies to the frame. There is also the added benefit of the oblong plastic doohicky that you can leave the screw in till you need it and is easier to find in your junk drawer than just the screw itself.
I realize that most of you have boxes that are labeled with myriad screws that you can find at a moments notice on your bench but for those of us who are less fortunate (and careless), this might alleviate some frustration when you can't remember "where" you put the original screw. (You may have to put a few drops of black paint on the screw if it's chromed.)