GW letters definitely work. You might not get all of them, but send a thoughtful and detailed one to each paid derog. Wash, rinse, repeat every other month, taking it higher withing the company if you can get better addys and departments... or names. Be nice and kiss tush frankly.
Do not apply for new credit until you see some FICO results from the GWs. I do think you need another major CC and higher limits, but first things first.
Very good about all of your open accounts minus Toyota never being late. GW Toyota too.
Call NY and Co, Dell, and HSBC and see if they can give you any sort of CLI without doing a hard INQ. A 'soft' account INQ is what you are looking for... it won't hurt your FICO and you might increase your UTI with no effort but a few calls.
Charge something small (under $30 inclusive of tax) on NY and Co to get it reporting. Let it generate onto a new statement and PIF. If money is tight, honestly I don't care if you buy something close to the cycle end date, let it get on a new statement, and return it for credit.
You should see a nice increase in FICO as you work to pay off your Dell card and get the HSBC closer to under 10% UTI.
You don't need score hits from hard INQs applying for CCs you don't know if you will get. You need one new card that you feel your chances of approval are 99.9 on. You might also want a line of credit on your checking account. See what progress you can make in the next few months before blowing INQs for nothing (or nothing great) though IMHO. Sounds like you are off to a great repair start and you know what you are doing.
EQ 787 EX 781 TU 737 11/17/07
*** I am not an attorney. If I was, I might not clip coupons. If you want legal advice, consult an attorney. If you want my personal opinion, feel free to consider my posts***