The Pepsi Seiko appears in a collection video from 6 months ago but is clearly stated to be owned by others. There is also a link to the watch mod website as an advert. I think that deal is more complex than the OP situation as it has a commercial B-B element and there was an agreement that a watch could be ‘kept’ for services rendered.
In terms of the OP Bogart watch I would make a clear communication that you no longer wish to support a video but that he can use any footage already obtained. You wish the watch returned to you with tracking data by ( list a date) or you will be reporting it to all relevant authorities and taking legal action for recovery. You hope he can understand that you did not anticipate waiting ?? Months to get your property back and that is why have lost confidence in the project and need the watch returned.
The guy is using his own identity and photo ID across multiple platforms / he travels and was at the London watch show and the Rock Band he was in still has some profile. He also owns / has access to a number of high value watches. He would seem to have very little to gain from appropriating a unique historic piece so hopefully this can be resolved amicably between you both without any third parties inflaming things (although this thread may have helped more than hindered). Time to take stock now and they hopefully come back with better news.