bridge/nut depth

Just received my "mountain dulcimer hardware kit" (tuners, bridge/nut, fret wire, anchor pins, strings) from Folkcraft. I'm building a cigar box dulcimer so I don't have any dimensional plans. Everything seems pretty straightforward, except for the nut and bridge.

How deep of slot should I cut for the nut (standard 1.5" molded delrin)?

Do you cut it shallow and then adjust for string height by sanding the nut down?

I guess the same questions go for the bridge?