It amazing how limited the primary sources are.  My campaign has recently been near vikland and I've been reading up on Norse mythology and sagas.  It's been fun to tie in things from my research into the game. 

For example:  a shield that is inspired by that "ship of Ullr" description for its powers. My players have it now and have not really figured out its extra powers even though they were used against them - hence spoilers

And, somewhat related, Oregon's foremost purveyor of bottom shelf vodka has released this fine drink:  https://www.hrdspirits.com/ullr-nordic-libation