I have never seen that type before but I would talk to "Dave" at
http://www.sixrobblees.com/ in Seattle just south of Boeing field.
I think that's his name. Been there well over 20 years, knows his stuff. Just ask for the part guy who has been there forever. See if you can e-mail him the pics so he understands what problem is.
If he can't help...I would do same thing to
http://www.autotiresupply.com/ (closer to first ave bridge)
Both are my "go to" places for stuff like that. For what its worth, ONE drop of removable lock tight on coupler nut. Not my, if a little bit is good, a whole lot is even better. For the type of coupler nuts I have I had to go buy a steel 8mm allen wrench to nuts off.
(And you do notice your torque spec at end of lug nut? I looked all over one day looking for it, and there it was stamped right into the end:))
IMO you just need longer studs.
www.autotiresupply.com/ web site doesn't have lug nuts listed but I think they have them.
If you do need longer studs, do it yourself at a later date to save ton of labor, don't let Les Schwab gets a hold of you. One of the few times on your RV you get to use a hammer and beat on something.