I loved my 1999 XR600 so much I got a 1991 to keep it company.
1999 XR600R (purchased in 2005 for $2000)
1995 CR500 forks (easy and cheap mod!)
5.8 gallon Acerbis tank (not yet installed)
Thumper Racing turn down for stock muffler (not installed yet)
Fat bar and clamp (not yet installed)
TM38 flatslide carb (not yet installed)
A few years ago after doing the fork swap...
1991 XR600R (purchased in boxes in 2007 for $350)
1996 CR500 forks (not yet installed)
1988 XR's Only head
-port n' polish
1991 XR's Only head (for sale?)
-port n' polish (maybe only on exhaust side?)
WB E Series slip on
Baja Designs DS kit
HSR40 pumper (not yet installed)
1986 WP Super Adjuster shock (awaiting reassembly)
1985 ATC350X oil cooler (eventual plumbing nightmare)
Moose tool bag
Acerbis handguards with blinkers (new, for sale)
In Dec of '07 before I put it in storage...
This has left me with scads of parts cluttering the garage like the original front end off of the 1991, a spare stock muffler or two, some tanks, and a whole bunch of other stuff that'll end up on eBay once I get off my butt and get them listed.