There is new language in the part-time wages section in this contract the says: "Part-time employees still in progression on August 1, 2008 shall recieve the above contractual increases and will be paid no less than what they are entitled to in accordance with the wage schedules in Article 22, Section 5 (b) below."
In short, you can not make less than a part timer hired after you, at worst you always will make the same. On your one year seniority date, you should receive a 15 cent raise. It was still advantageous to get hired before the new contract, because you will now slowly get bigger raises than new hires.
On August 1st you should be making 10.375 if being paid at the unskilled rate. Good luck.