I used my GI BIll to earn all ratings after my PPL. You currently qualify under the old rules, but may be out of the 10 year window since your separation.
If you are within 10 years since separation: Find a 141 approved school right now, and get started. The old program pays 60% of your costs under the approved school 141 syllabus. I don;t quite know what the new program will cover, but as I understand it possibly up to 100% (the way it should be).
Either way, when the new program rolls out this spring, your GI Bill will be for the full ballance, as if you never used any education money - including if you used the maximum ammount under the old program.
*** When you call a school to find out if they are approved... just ask if they are a "VA 141 school." If they dont know what you are saying, they are not one - the program is difficult to get approved for the FBO, so once they get it THEY ARE SURE OF IT and recruit qualified students.