MoHops posted last week that he's used clear silicone, and then put the call in the freezer to take things apart. I'd just glue them together lightly, and then try this. Sounds like a great way to approach trial and error to me if it works out.
I've never heard of such a thing before this. No doubt you've got to have your surface and sound board glued down, and the glue dry before you know what kind of finished tone qualities you're going to be able to get out of the call.
Before I did this, I would also build some kind of 'tool' that puts a small dowel rod down in each of your sound holes to help pop things out. The way I see it, you're going to pop your sound board, and then push IT against your playing surface to free up both.
I'd sure only do this on one call to see if it will work prior to doing it on all of them.
I'm looking forward to hearing of your report back!
Parker
