If you are starting with standard Hornet brass and will fireform it, use standard Hornet data for the first firing. There's no data for an old powder with a new bullet, but my Speer #9 manual shows W680 at 11 to 12.0 with a 40-gr bullet. You ought to be able to use that with a 35-grainer safely.
Assuming so, you can then work up in safe increments until you better your velocity by perhaps 5%. I'd use 0.2-gr increments (about 2% of the expected max of about 13.0, rounded down) and look for a final velocity of about 3150 or so (105% of factory 3000 fps Hornet loads with that bullet).
