I have never had any old Delta 3200, but I know that Tmax is a very touchy beast - and I understand the two are of similar type.
I was raising an eye-brow, thinking "Yeah, right..." when I read that Tmax 3200 will be affected by cosmic radiation ( I am not making this up!).... Until I saw it first hand. It is, and it is noticeable. Its an intersting effect, but completely unpredictable, so really of no use, creatively speaking. I am also unsure weather this applies as much to unexposed film, but I believe it does.
I would not risk that roll of film on something very important - more as a "hey, what the heck - lets see what comes of it" experiment.
And the roll I am talking about was several years old.
I would feel better if you verified what I wrote here with someone who can give you more definite answers, as I realize my input here is more than a little sketchy - I would hate to steer you wrong. Best of luck,
Peter.