What Mike said on one hand, but it would also help if you were more specific (1) about what type of dog lock - Jacobean, or a later WR/AR martial type, or a finer civilian piece? - and (2) what are you going for in the finished musket? A military arm? Civilian? Restocked parts gun?
American parts gun with ca. 1716 + or - Swedish dog lock (2 screw), earlier French guard, thin sheet sideplate similar to a couple used on pre-land pattern Besses.
Early Hudson River gun using a recycled Queene Anne doglock:
Queene Anne period sea service doglock (this sideplate type was used on infantry muskets of the period as well, I believe):