AKFireMedic...

Can't help with the JR question, I'll leave that to others.

On the hinge seal...I like to do that. Many do not and I don't think it makes any difference on flying performance. But here's how I do it. I cut an inch wide monokote (I use clear or sometime white) I bend the monokote length wise and fit it into the slot. I then iron (use 280 degrees for me) the monokote on the sides using the side of the iron on the angle of the deflected aileron/elevator/rudder surface. I iron firmly and quickly. Don't let the surface get too hot or it shrinks the monokote too much and tries to close the hinged surface. Make sure you get the sides ironed good but don't touch it in the middle of it will shrink and not be flexible. I almost always have a wrinkle or two. But it generally doesn't look too bad.

Really helps with clean up as well.

thanks
Barry