Greetings, I'm a long time Prestashop developer, i've started with the 1.4.2.1, and have worked on all the versions up to the 1.7, i've been part of a Prestashop platinum certified team, where i was i care to develop custom modules and core changes.
I'm able to start immediatly to work and fix your problem with Ebay module.
I will just need access to your database/ftp hosts, to check the logs, and fix the code/database data in order to make the module works again and be able to import orders.
I hope to be able to work with you, Sincerely
Francesco