John,
You've allready got good advice- tune down and watch your string guages. I can add this info- a bit more specific...

I own a 70's era Ricky 12. It has a double trussrod, which is one long piece of metal bent in a U shape- there's 2 nuts to adjust the tension.

The threaded part of the rod got tweaked and you can't adjust it because you can't get a wrench on the nut. It might have happened because I used too heavy a guage set of strings. The Ernie ball '12 string light' set has a .009 on top and .046 for the fat E- I think that's the set that tweaked it. The Kaman 'Electric Light 12' set had a .041 for the fat E... they are hard to find- especially here, I have to buy single strings to make a set.

I keep it in standard pitch. I didn't fix the trussrod because it's hard to find anyone- anywhere- who's willing to do it- even the factory. With light strings, and I lowered the bridge, it plays fine, tho Rickys have a very narrow neck, and if you capo up, it feels like a mandolin.

I love the sound of an electric 12, you immediately get the vibe of all those great Byrds and Beatles tunes...

Good luck with your music... MIke