Maxing out Event Buildings

[The Froggle]

It looks like, short of spending a bundle on Diamonds (probably not going to happen since I'm on a fixed income), I'm going to be 1 or 2 upgrades short of maxing out the Animal Crossing EB. So, I've got some questions, as I've been on FOE less than a year.
(1) Is there another way to be sure get the upgrades once the Event is over? If so, how?
(2) Do the upgrades ever come up in the Antiques Dealer building for EBs? I think I saw one, once, but I'm not sure.
(3) Is it possible to trade another EB for an upgrade? If so, how? (I've got a Golden Orrery Selection Kit, for example, and that building is already maxed out.)
(4) Assuming I'm patient enough, it seems like these Events are annual? Is that correct? And if so, if I'm patient enough will the same EB & Upgrades also come around?

Thanks for any help you can give on the 4 questions above.

 

[MJ Artisan of War]

1 & 2.... Yes they will appear in AD one year later, right after they appear in next years corresponding event as dailies... those are the two ways to get more event building levels.....

 

[Bian Mian]

3: no
4: maybe.

 

[Ebeondi Asi]

added on 4: yes the events are annual.
Also: Generally most main prizes next year are in the Daily type prizes.
Like last year the Mountain Reserve was the main prize and this year it came up as a Daily
(Though sometimes not. Like the next coming Event in Beta the Pirate's Hideout is not being given as a Daily this year even though it was the main prize last year. they are giving the Govenor's mansion as Daily which is also a desirable prize from the previous year)

 

[The Froggle]

Thanks for the quick answers. You folks are great about that!