Thanks you all for your opinions.
I respect everyone's thoughts on the matter.
The reason why I bought them in the first place is that I already had in mind to turn them into closed toms since they already had a bottom reinforced ring/bearing edge. Plus I got all three of them for $30.00 a piece!! Can't beat that. They also have the granitone interiors which to me have always had that yucchh look to them. Don't know why they even bothered spraying them with that stuff, they always looked so much better "o-naturel".
If concert toms do make a comeback, I am prepared to live with my decision (although if they do return, I can't see them sticking around as long as they did in the 70's/80's - I think it will be a flash in the pan fad).
I have 4 chrome Slingerland concert toms from '74 that are the best concert toms that I have ever seen in my life - Slingerland or otherwise. With the original stands too.
Anyway, I haven't touched them yet, have been reading what everyone has said.
I also have to agree that concert toms have never sounded that great. I wouldn't bother with these if they didn't have the bearing edge on them already. I can't see these drums sounding any worse by putting a bottom head on them. I personally think they'll sound better.
Won't be doing anything yet, it'll be awhile yet before I do. Just wanted to ask about the whole process before diving in.
Thanks to all once again.
Happy drumming!