You've probably got some .451 or .454 balls for you wheel guns, see how they fit.
I've got a Spanish made Kentuky 45 that works OK with .445. You'll need to do a trial or error with your patches til you find something that fits.
When you do get done shooting it and get to cleaning it; high side your rod and pay attention to it and that'll tell you your rate of twist. 1:60" is going to want balls not REAL , MAXI , or Mini bullets. It'll digest them but apparently accuracy suffers.
Start out with 50-60 grains of FFG and work from there.