Basically, the only thing thats compatible between the R31 boss and the 200B column is the spline, you have to mod the car to make it fit

*Disclaimer: I only put the boss on because it was free, it had been sitting in my bedroom for a while because i stole it out of an R31 that I bought then sold 6 months later
People wanting to do things right (legally), or want their car to look good, or people who have to spend cash on a boss, should really look into a 200B/910 Bluebird boss

SO
what I did was
-took the original steering wheel off (my car is SX so it had a factory boss) just have it so theres nothing to do with the steering wheel there, just the spline staring you in the face
-take off the little 2 piece taper thing (you'll see what I mean when you take your wheel off) its just a 2 piece taper thing held together with spring steel wire, it cant be on the car because the R31 boss doesnt have a taper where the 200B wheel/factory boss does
-take the ignition/combination stalk shroud off, and leave it off (smash it, see if I care)
-undo the screw down the bottom of the combination stalks that clamps them onto the column, you have to undo it a fair bit so they can come out of the lip they sit in so dont stress if they dont want to move when youve only undone it half a turn
-you want the combination stalks away from the boss so you bolt the boss on properly, you may want them as close to the steering wheel if its a daily driver, but my car is track only so I moved them as close as I could to the ignition barrel without making it a pain to hit the key, that way I cant hit them accidentally in a motorkhana
-strip the boss so theres nothing on it, no horn button, wires etc
-bolt boss on
-bolt wheel onto boss
-and youre away

And the gist of this is you have a sports steering wheel, no horn, and non-cancelling blinkers
But I did it because it was cheap for me, and my car isnt registered
There you go
-Nick