Building credit to pass a mortgage check

[pippy0512]

i want to know if anyone has any solid facts about passing a mortgage credit check. I have 2 CCJ's from 4 years ago, and 3 settled defaulted accounts that are 3 years old. The CCJ's are not settled and wont be anytime soon, however i realize they drop of my credit file after 6 years, my girlfriend really doesn't want to wait this long! So my Experian sits at 834 (good) while my Equifax sits at 325 (not so good). I am slowly rebuilding with a low limit credit card but would love any advice on when best to apply,who with,chances of passing. The last thing i want is a mortgage refusal on my credit file! also is it true lenders have an 'off the record' credit system that is just shared amongst themselves or is that just paranoid!?