Joined: Jan 2010
Posts: 9,779
Likes: 1,748
From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
Most important thing when bending fork blades or stays is to have a reference point from which to measure the progress during bending.
The opposite-side fork blade or chainstay can provide such reference, as long as it is not being subjected to any loads during the straightening.
Blocks of wood can prevent the localized loading that might dent tubing or cause too much localization in the bend location.
You can sight across the side profile view of the fork to determine what is needed to make the fork blades parallel and with identical shape/bend profile.