Paul:

If we are talking about a large plane, Du-Bro part number 205 is a 4-40 kit for tailplane support.

For a smaller plane just get some aramid or kevlar cord, drill a hole through the vertical fin - in a spar if it's built up, anywhere for solid - and a hole near each outer end of the horizontal stab. Thread the cord up through one end of the horiz stab, through the vert, and back down through the other end of the horiz stab. Pull down on one end and drop some CA on the top side. then go to the opposite end and pull that one down, tightening the cord all the way across to the other side, then another dab of CA. Finally, put some CA on the cord where it goes through the vertical stab, trim the bottom and it's all done.

Now for problems. The aramid/kevlar tends to stretch a bit when first put in service, so before you put the cord in the plane tie one end off and pull hard on the other, yank the heck out of it to get the initial stretch done.

Added insurance against going slack - soak the entire cord with CA after installation.

An alternative to the cord is getting a small "Pull-pull" rig and adapting that.

Hope this helps.

Bill.