Like you I have a box of 135 grain lead 9mm. I use bullseye am going to try 3.1 to start, this is in the middle of the 130 and 147 grain loads.
My lyman book does not show 135 grain either so for unique I split the difference between the shown starting grains and came up with a starting load using 3.35 of unique.
I`m not suggesting you try this, I`m going to, it should be ok as it is at the lower end of the scale.
The place where I deal is selling the 135 grain 9mm for $25.00 for 500. Reason for the low price is that most shooters are using the 125, 130 and 147 grain bullets.
Hope you find a good recipe that works for you.
jaydeee