Two things I can suggest:
1) See if you can CLI at least one of your cards to $5k or higher.
2) Try leaving a small balance on one of your cards (between 1-7%)
Your score may go up or stay the same as you had only one card before, the sweet spot is 3-5 cards so its a possitive to add a couple new cards that may take the sting out of the new TL's and INQ's you incurred.
At 61 days you can request a 3x CLI from AMEX on your BCE card, After 6 months you should be golden for just about any card you want and can afford the AF on.
Why would you want your score 750 !??? I not make much diff from 720 to 800........
Ha! Your asking someone on myfico why they want a higher score...people that tweak their utility to get any extra points they can!!!
We are credit nerds!!!