Hi,
OSC expert here. I suppose they are based on option types, but your old shop says 2004 so I may be wrong. Anyway I can do what you need keeping the compatibility (if you copy all the old data).
Relevant Skills and Experience
17+ experience in web programming PHP, MySQL, HTML, CSS, JavaScript and many other
11+ years experience in OSCommerce
12 years since my first project with freelancer (just check my reviews).
Proposed Milestones
$100 USD - You don't have to release any funds until you are 100% happy.
Do you have other custom mods you need to be copied?