Wanted: Damaged / Unwanted 17inch rear rim

[heti]

Where could I start looking for an unwanted (damaged) rear R17 rim to practice fixing rear punctures?  

I have only done this once and realised I will need to get a lot more practice before attempting solo trips far away from civilization.  I suppose I can practice on my GS's rim, but I'm afraid the powder coating will all end up on the garage floor!   :-[