I have recieved my first side rod gas loco and the bell comes loose. Where do I mount it on this loco?

I just purchased my first side rod gas loco and it came with a loose bell but no suggestions or hints on where to mount it on the loco. Suggestions please.

I have just repainted my 2-6-0 loco and am going to set it  up to look like
the C & S 21.  I have already completed a 22  but now I need help in
getting the correct size decals.  I do know that the  Champ set for locos in
O guage is  to large and long for the tender.  I need a set that has the
lettering for "Colorado & Southern" not  over 2 & 7/8 inches long.  This will fit on  the  side of  the tender just right and be al close match to the lettering on my 22. Not too much shorter than that either or  else it will not look well  next to my already completed 22.  Any suggestions  will be greatly received.