I have recently done a swap with my Legacy GT and a friend of mine suggested I post my solution here... I simply modified my stock 5-speed knob I work at a machine shop and got one of my coworkers to align it in a vice on a manual mill and drill out a one inch deep recess at just under .800" diameter (.785-or something i can't remember exactly) in the white plastic core of the knob it left more than enough thread to use the knob securely.
Though I could have gone with about .050" or so less and been fine but any more than i did would have completely removed that section of the core which honestly would not have mattered much except the white plastic allows the lockout to slid better when pulling on the knob causing a slight flex in the rubber at the base.
I did pull the leather back from the rubber that makes up the outer body before drilling so as not to shred the material. After the core was drilled out I trimmed about 3/16- 1/4 inch off of the rubber that remained at a rounded edge. Then trimmed off some of the extra leather some then glued it down with a very small amount 3m automotive adhesive.
Lastly I pried off the clear plastic piece with the 5-speed shift pattern printed on the back of it scraped and polished the pattern off of the back and I'm going to try to have a small Subaru stars emblem cut from vinyl to replace the shift pattern.