Hi Tim and welcome!
I used the Ovation MM68 as my primary stage instrument for seven wonderful years until it came to a tragic end. I had mine tweaked by a very good tech to adjust the action. It's done with shims and some very scarry filing (never watch what a tech does to your beloved instrument in the secret back room or you'll faint dead away!). He also added a Sabine Stealth tuner with the electronics hidden inside and a mute switch that allowed me to tune without the whole world hearing.
Being a mandolin, it can't ever be really guiitar-like, but it can be adjusted quite a bit more than you'd think.
As Ted mentioned, I believed there's only three labels you'll find for the Ovation mandos. The headstock will say 'Ovation' for those built in Connecticut, 'Applause' for those built overseas, and the 'Adamas', which is so rare it's more of a legend than an actual mandolin.
Dedicated Ovation player
Avid Bose user