Thanks for the input Jeff, always glad to hear from you. And now that you mention it, veneer is probably the way to go on these.
I mentioned in another thread about the birch veneer available close to me. Long rolls, no need for seams on bass drum, and although it looks like some of the rolls have horizontal seams/joins, it would be totally fine for painting.
If I had the dough, the ginger glitter would be it, and I'd have Precision install it too. But I was remembering how good that DIY gold sparkle turned out [much better than it looks in the pics], and still toying with the idea of trying a silver sparkle. If I can get the sparkles sandwiched between two sheets of Dura-lar [preferably straw-tinted], with the Krylon glaze, and still pliant enough to wrap around the shells, I'd use the seam-taping-only method. Because wood gluing the rough [sparkle] side to the shell would leave an awful mess if I ever wanted to change it out...
[edit] I know what you mean about getting the shells smooth - tried it with some MIJ shells with the vertical grain...which I could never get to completely disappear.
Mitch