The Dungeoneer's Handbook on page 24 is a Key-wound Rattler. Am I missing the craft DC and the requirements, or does it simply not have any ? If they are missing, what would a reasonable proposal for them to my DM be ?
It's not a wondrous item. It doesn't even appear to be magical. Just Craft(clockwork) ?
Couldn't find any craft DC relating to it.
Personally, relate it to the existing clockwerk soldiers/servants.
DC 20 for craft(Clockwerk) for spy, soldier and familiar.
I'd go with DC 20 for the rattler as well.
YMMV
Edit: Realized rattler cannot be "programmed" with an action schema.
Personally, would knock 5 off the DC to simulate "Don't need some prerequisite for the programmable clockwerks" to bring it to DC 15.