Here's the stock setup before I started for reference.
Here is the stock unit, a PS13 master cylinder with remote reservoir, and a PS13 integrated reservoir.
Here is the integrated reservoir (KTM Part# 54813060100) master cylinder mounted. It literally hides behind the heel guard.
The Buell master cylinder mounting screws worked perfectly. There was no adjustment needed.
The brake light switch threads are different between KTM and Buell. So I ordered a (KTM part# 50311051100) KTM rear brake light switch. When it comes in, I'll simply swap out the wiring connectors.
Tommorrow I will make a run to the hardware store to find parts to build the linkage.