It really depends on how detailed the moulding profile is. There's a certain level of detail -- like if the profile has small beads and/or coves, like one produced by a classical profile router bit -- that will be too refined for any pad you make on your own. I would definitely experiment on a sample piece before you use it just to make sure you don't ruin the profile. If you have a stationary sander (like a disc or an edge sander), it's fairly easy to erase a custom profile you've already made and then cut a new one.