I always go in first, tell them what I have, and what I want done. if they have the spot open to work on it (good smiths are always busy, and my local gun wrench is no exception!) I'll bring it in cased and unloaded. If its a mag issue, I'll also bring in the wonky mag, unloaded, in the same case. A lot of times they're backlogged, so I get on their books and bring it in when they have an opening.
Part of the reason I thought about taking smithing courses was because Tim told me on simple jobs "Darn, you ought to be able to do this, Sue" so I am getting intriuged, but he's good... y know.
Oh yeah, discretion. Feel for your "Spidey-Sense" about the place. If something doesn't feel right, it usually isn't. If part of what you're having worked on is, say, a certain style of black gun and you're on the left coast, for example, and you get the feeling that having said smithy work on it will earn you a visit from the local constabulary, don't discount that feeling... a friend lost her AK collection by not listening to that feeling. Or if you get the sense that something won't get done right, trust your gut and leave. This is why I --always-- do my footwork sans firearm in hand. Even my benign 11-48 claykiller stays trunked until Tim (or whoever) and I talk about it... and anyway, there's usually a cup o coffee and catching up to do first.
There's the biggest thing of all. KNOW your smith. If you can't hash shi, er, stuff with him (or her), then I'm not sure I want them messing with a member of my family!
Good luck... an inheritance like that is a true sign of your dad's love for you, be honored for that!!! Susanna