mtn-man: Sorry, but you cannot convert a traditional cache to a virtual cache simply because you don't want to replace it. I am going to go ahead and archive this cache based on this from your own description:
"(if anyone complains, then I will have to archive it)"
If you can fix or verify this cache it can be easily unarchived. For now I am going to archive it. Feel free to contact me through my profile linked below if you fix it.
NOTE: If you have any questions, do not reply to the archive note email. Click on the link to go to the cache page and click on my name in the archive log at the bottom of the page. You can then send me an email regarding the cache. Please send me a link to the cache in question so I will know which cache it is regarding.
Thanks for your understanding,
mtn-man
Geocaching.com Volunteer Reviewer
My profile page:
http://www.geocaching.com/profile/?guid=bc877f93-1fa3-43a3-9ef2-7b2446d08578