In this thread here, anthonym quotes an e-mail from Mike Barnby about refurbishing wheels which reads, in part,
"take centres out and refurbish - includes crack testing
new bolts (automatically whenever disassembled), washers and nuts (not wheel nuts!)
edit: refurb includes repaint, since it has to be blasted paint free for the crack test."
The additional cost will be well worth it for peace of mind, if nothing else, IMHO.
- Sean