Get a set of thin flexible plastic cutting mats from BedBathandBeyond. You can cut these into any shape for guitar top protectors, soft scrapers, templates, and many other uses. I like the Dexas brand. Cheap and handy.
Also, tougher and more useful than the old single edge razor blades are Milwaukee Model 48-22-1954 carton utility blade. These have rounded corners instead of a sharp point. They are much less likely to scratch adjoining surfaces, they are extremely sharp and last far longer than the old window scraper single edge blades. I put a piece of electrician's tape across the back of the blade.
For neck re-setting work, a Buck Brothers 1/8" bevel edge chisel is very convenient. Newer bevel edge chisels are too tall as measured from the blade flat side to the top of the bevel. Get the longest chisel you can find.
How about a top plank edge jointing jig? See attachment. This is a Veritas Shooting board plane running against a four foot aluminum straight edge embedded in a plywood jig structure. It works like a giant bench hook with a mahogany board on top lined with no slip rubber sheet. Pushing down on this prevents the top planks from shifting when the plane is run through. In the image you can see a plank jointing operation in progress.