Okay, comments are only allowed on trade threads when specifically asked for by the OP. Since you have asked, here is my opinion, which of course is simply that: 1 person's opinion.
I have played VMK since March 2006. The green flip hat was already retired at that time. So, the only people that have a green flip hat are those that have either been playing for over 1 1/4 years OR those that traded for 1.
That would logically lead to the belief that there are probably not many people still playing vmk that bought many of them and still have them. So your pool of ppl that have 1 they are willing to part with is relatively small, imo.
Now, let's look at the items you have offered:
Mickey TV - relatvely difficult to find people with many, but still available so supply is growing (opposite of green flip)
DLR pumpkin - retired, was available for a short time period, strong trade item, but many more ppl still playing that got pumpkin compared to green flip.
DLR blue Christmas wreath - retired, but has been available at holiday quest item for 2 years in a row now so would be logical to conclude there are many available.
x2 Jungle Cruise Rhino posters - not sure the history of, but I believe in park quest for a relatively long time (could be wrong here)
x4 Matterhorn Host Pins - recently retired, plenty available in game
Animation Viewer - current in park quest item, not super easy to find in game, DLR VMK Central closing makes it less available than previously
So, the items you are offering are not as rare or difficult to find as a green flip hat, again only imo. That said, if someone with several green flip hats does not have / has not had access to the parks, your animation viewer, DLR pumpkin and possibly blue wreath are great items that would be of interest.
You may need to add some more rare items and / or wanted items like pirate quest, snowmen, HM pins, etc....
Just my opinion. Maybe others will offer theirs. Good luck! And remember it' out there. Patience and persistence.
