OsCommerce Old Addon recode for TomatoCart

I have had a look at TomatoCart which is OsCommerce based but has a fancy admin back-end. I need some "contributions" from older versions of Oscommerce ported over to add features or if it's easier to code it from scratch then do so. Feature : Ebay Integration Allow Ebay auctions to be posted direct from OsCommerce back end, display auctions on front end, add Ebay Box with rotating items. Consider that version of PHP and MYSQL has changed since the original addons were created for the older OsCommerce versions. I would prefer to work off the TomatoCart distribution or install that back-end on OSCOMMERCE 2.34 as the back-end is super user friendly, but needs more customisation to get it to do what I want.