I am not in any way linked to the publisher of this, except that I have in the past made an order with them. Merriam has for years now provided a very good service to researchers by making available (at low cost) material that otherwise would be extremely difficult, if not impossible to get, and require mortgaging your house or selling off your first-born to pay for it, such as original unit histories written shortly after the war, or post-war studies done by German generals for the Allies.
Today I came across this one on Google books:
4th Armoured Brigade History – with the chapter on the relief of Tobruk available as a free read.
To order it go here – it is available very cheaply if you are happy with the PDF. If you wanted to purchase the original now, presuming you could find it, it’ll probably set you back by about 100 dollars.