I didn't look to much further into it because I found and ordered a rebuild kit for the starter on my 06 Speedy.
Perhaps some time comparing fiche diagrams and part #s on bikebandit.com or a similar page will shed some light on their potential compatibility.
Have you pulled the starter from your 05 and compared it side by side with the unit from the Street Triple? Same number of splines etc? Disassemble, and see if the brushes etc will fit?
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