I ended up going ahead and letting the installer do whatever, then I removed the logical volume. The howto (http://tldp.org/HOWTO/LVM-HOWTO/removelv.html) is not so helpful about helping you figure out what you need to know. Unfortunately I clobbered my history file & don't really know how I did it.
I'm still not sure whether this process would have clobber3ed the contents of the disk. Dave