The Minn Kota bracket is their standard bracket and is used on several Minn Kota trolling motors. You can pickup the complete transom mounting bracket complete with tilt for about $32 + shipping (USD) from FISH370.
I used a Dremel Tool with a thin cutoff wheel to remove the stock tilt detent area from the bracket.
The aluminum bracket is made from aluminum channel and angle.
In order to couple the steering and tilt mechanisms to the stock Minn Kota shaft I first cut off 4″ of the stock composite tiller motor shaft using a pipe cutter. This step must be done with care. You don’t want to crush the composite shaft. I found it helpful to use compressed air to keep the grove you are cutting clear of debris.
I used a piece of 0.875″ OD drawn aluminum tubing to fit inside the stock composite shaft. This tubing is a bit large and a few thousands need to be removed. This tubing is locked into the composite shaft with some #4 hardware. The other end is coupled with a ServoCity 22mm Bore, Face Tapped Clamping Hub, 1.50″ Pattern. This clamping hub is then fitted to a ServoCity 1″ Bore, Face Thru-hole Clamping Hub, 1.50″ Pattern. Into the 1″ clamping hub is fitted a piece of ServoCity 1″ OD tubing. The 1″ tubing is about 10″ long but best to make it longer for starters. Always easier to make it shorter the longer.