TF frame mount Booster/Master, what is this bracket?

[jkmhb]

Please see the pics, there is an extra bracket I thought would go from the bottom outer booster/bracket bolt to the center pivot bolt, but it is about 2 inches too long. I can find instructions for this setup anywhere, I bought it off ebay (I know). I'm also trying to figure out what the small bracket in the first picture with 3 holes - is for.

The second picture is a close up of the bracket in question. It looks like the number on it reads MBMBPRCP5559