If you look up one of the 2017 Loyalty Items it tells you the set bonus below. The set is 8 pieces, hat, slippers, mitten, snuggie, ring, earring, golden egg jewel and undies. Has a really good set bonus.
I was just guessing there was only the 8 piece bonus. Maybe someone with a full 5 piece set, ring, snuggie, mittens, hat and boots, could test. I think that at least Samtook has the full 8 piece set, maybe he would test and see if it gives any bonus.
Wearing the 4 armor pieces + Bunny Queen Ring I gained 1000/hp and about 400/mp. Also looks to be +8 to each stat. Gained 20 AC and based upon the add to WIS and the +7mr for last itime, i had 82 additional MR.