i have just done my rear cross member on my 110. i too thought that the prices were very high and so chose to fabricate my own. a local steel work company bent up a piece of 3mm sheet into the basic U channel and then i went from there. they charged me £25 which included a rumage around in their scrap bin for all the other bits i needed... it too me around six hours to fabricate including welding it to the back of the 110. i chose to completely remive the tub and am glad i did as it made things alot easier - obviously the fuel tank had to come off aswell (empty it before you unbolt it - very heavy otherwise especially if you're sat underneath it..!). my only word of warning with this approach is that the five tabs which connect the tub to the x-member should be bolted to the tub and then welded to the x-member otherwise you may have a job matching them up... good luck.