This project on Instructables(r) can be modified as needed. The basic instructions are clear and easy to follow.
http://www.instructables.com/id/Pegroll-the-Foldable-Tool-Oraganiser/On change I would make is to use a sheet of 1/8" polyethylene plastic as the pegboard material. It is flexible enough to roll into a tight bundle and should last for years if properly cared for...
This bundle of tools will fit more readily into a BOB or other backpack. It is certainly smaller than a comparable toolbox.
On item which could be added is a compartmented plastic box for items like nails, screws, bits or other small items. That box could be rolled inside the bundle.
I note that the rolled bundle, inside a small, waterproof plastic bag, will allow you to strap it outside of your pack, similar to the way a sleeping bag is carried. That saves interior space and give quicker access to the tools.