What are your expectations? Really, there is no reason to remove that etch and urethane primer. MOST shops around the country wouldn't do it any different. For that matter many (if not most) wouldn't even use the etch and apply the urethane over the bare metal.
If you are after the most wiz bang job you can get, strip it and apply epoxy. If you are simply after a nice job that 90% of the cars you see repaired or restored have, work with what you have.
How much filler work are you going to need?