rootboy- There is a very simple way to check fork alignment without expensive tooling. First is the need to understand the axises of alignment. Drop outs need to be the proper width apart, centered on the axis of the steerer. Drop outs (blades included) need to be of equal length from the steerer/crown. Ideally (but not actually needed) the front axle should be parallel to the fork crown. Lastly the drop out faces need to be parallel to each other.
Drop out width is pretty straight forward, being the same as the front axle OLD. Easy to gauge with a wheel or measure with a ruler.
Face parallelness can be checked with an axle bolted into one drop out and extending just to the other drop out's inner face. How the axle's free end lines up with the second drop out shows how parallel it is. Repeate for other side.
Axle/crown parallelness can be compared with an axle in the drop outs and a straight edge placed across the top most part of the blades. Sighting the two straight edges (axle is one edge) shows this comparison.
Blade/drop out lengths can be checked with a centered (dished) wheel placed in the drop outs and looking at how centered the rims is between the blades upper portion.
The last two alignment aspects is a little bit trickier and requires a home made tool. If you placed the same wheel in the drops and were able to sight through the steerer and the rim's valve hole to the wheel's other side (about where it would touch the ground in use) you effectively have a straight "edge" close to 3' long. The tool that lets you sight down the very center of the steerer is a piece of small diameter tubing (maybe 1/4" ID) with masking tape wound around it in two places along the tube's length. the tape is wrapped around the tube just enough to become a centering shim and slide into the steerer. So you end up with a sighting scope of sorts running down the center of the steerer. Rotate the wheel so you can see through the valve hole. From the top of the steerer's sight tube look through it, the valve hole and you'll see the rim on the oother side. How centered is the rim in the field of view shows if the wheel is not in line with the steerer. If the rim is centered between the blades by the crown and the viewed rim if off center the blades are not centered WRT the steerer. If the viewed rim is centered and you then loosen the axle nuts (or QR) and let the rim settle into the drop outs fully and the rim is off center between the blades then one blade is longer then the other (or one drop out slot is not deep enough).
I usually do the steerer/drop out centering first (ans set the width at the same time), then the axle/crown parallelness next, drop out face parallelness next and blade length last. i'll go round this process a couple or three times to make sure one adjustment hasn't affected another.
I came up with this system a long time ago and have aligned a lot of forks over the years, in the shops i've owned or worked in and in my own building. Included is a photo of the sighting tube resting ontop of a steerer with a wheel in place. The sight tube would be slid into the steerer during actual alignment checking.
I now have a precision fork clamp mounted on my flat surface (and then can use height gauges and machanist's squares) and have checked out how this compares to the my steerer sight tube method. They tend to agree with each other to a high degree. Andy.