Fiberglass Detachable Horns Help

Here are the horns in their current state.  Are approximately 11-12 inches long, and are fiberglass coated insulation foam. They are very strong and lightweight. There are some noticeable "flaws" in the surface, but I left them in there on purpose. Horns are usual bone, and they are not perfect, so realistically these were not make perfectly on purpose. (making them perfect woulda just required a bit more body filler and some sanding) 


So here is my question. What strength of magnet do you think I will need to attach these horns? I am thinking that a triangle like pattern in the bottom of each horn consisting of 3 magnets would work well. And then attacking some Velcro where ever there isn't a magnetic surface.

Would something like this work?    http://www.kjmagnetics.com/proddetail.asp?prod=D9H2

I tried doing a small sample with only using 2 magnets that have a rated pull force of 2 lbs each, but it was somewhat weak. I was considering a few options. 

1: Embed 3 magnets into the base of each horn (drill and epoxy), and then also 3 magents in the head, and fill it out with some velcro
2: Attach a steel plate to the bottom of the horn and then only put the magnets inside the head. (the thought behind this was that I                    
    could get fewer stronger magnets and the extra weight in the horn would counter balance the horn, but the horn would be a bit    susceptible to being  shifted easily)
3 Putting in some sort of rod (perhaps a reinforced dowel)  on the head and then having a complimentary hole within the horn, and then using magnets to firmly hold it on.

Sorry for this being so long. Any ideas?