You can submit updates to GURPS Third Edition material for GURPS Fourth Edition on GURPS Wiki. However, you must be aware that Steve Jackson Games retains the ownership of such material. If they ever publish the official updates in a sourcebook, it will obviously look a lot like what you posted here. Steve Jackson Games won't owe anything to you, as you based your work on their stuff in the first place (both the original material and GURPS Fourth Edition!). Posting updated material for GURPS Fourth Edition is therefore something you'll do for free, without getting any rights on it except the right to rejoice for giving the community some useful and valuable stuff.

For more information about this, you can read this thread about 4th edition updates and more specifically this post from Ellie The Technomancer who gave some legal information on the subject.

If you have any question, please contact Steve Jackson Games directly.