kubota 2920 snow blower sub fram brackets/

[great4me]

I have a Kubota 2920 and a b2781a snow blower . It did not come with all the parts, the parts that you have to put on the tractor to hook up the sub frame, I had to buy
and am trying to install them, they are 2 black brackets with shims longer bolts and I can't seem to get the brackets flat.....it shows 2 holes on each side but looks like you could put in 3 on each side...
from the diagram I have it just puzzles me any one have one or done it??

Thanks for any help or pictures//