Shields!

[richsc]

One thing we (Legio XX) found out that makes this press a bit easier, is that you can buy bendable plywoods, usually birch, that bend on either axis. This stuff can almost be bent into a 1 foot radius for some types. More expensive than the usual 1/8" luan, but so much easier you almost don't need the shield press.
Locally, we buy ours from a hardwood supplier, Colonial Hardwoods, Virginia, who stock a few types in the usual 4'x8'.