Right then - first off don't take this the wrong way, but......
I've got to be honest and say that you have a pretty much complete original survivor there and it would be nicer to see it stripped down, cleaned and put back together maybe with some replacement tyres and grips and it would look great but you sound like you've made your mind up so hey-ho. Secondly i hate seeing bikes stickered up as something they are not - you may sticker it up as a cali and eventually get bored with it and sell it on and although you may be totally honest about the bike, the next guy may not be when he puts it up as an all tubes chr-mo cali rather than an all tubes HT steel M1
Anyway, that aside, it's your bike so here is some info for you.......
They did a 1985 cali which has the red/yellow decals with a headtube badge and they did it in white that year also. Problem being in 85 the headtube badge was riveted and couloured whereas yours will be black/silver and glued on.
Here's the headtube on one of my 85's :
Your best bet really is to go for the 1986 decals as the headtube was the same in 86 and 87.
Here is my 86 cali in case you are unsure what the 86 decals are like :