I'm glad you're getting some ideas here. That's the main point of my sharing, just in case others want some ideas for their own projects.
I really do love having the hay ring under the loft. Years past we fed out under the sky and when it rained, well, the hay got wet. That's how everyone around here does it and it is wasteful. If one has the option to feed hay under roof they should.
OldGardener said:...when the door is down, the barrel is too thin to seal the gap...
I completely see what you mean here. That is really interesting as mine has no (visible) gap when the door is down. I'll go out there later and inspect it more closely and see if there's a gap if I get up there and look more closely. Your adding a fascia to close the gap is a good solution.
Of course, the raccoons will just jump in through your open dutch doors.
I solve that problem by placing a bounty on raccoons. The children love getting a dollar for every one they catch.