(Not lost but not easily found in mounds and mounds of paperwork). No certified copies were made. Original was not filed with court clerk. Plain copy cannot be filed with court clerk and some institutions require seeing the originally-executed POA. LO can no longer, legally, execute a new POA. Is there any recourse at all in such a situation (other than going to the expense of guardianship, which may not work at this point anyway)?
The exception is if you need to work with an out of state bank (such as credit card banks that are mainly never near you)...nearly all of which will accept a certified copy (not just a photocopy).
Without the original and with no certified copies I believe you will not find anyone to work with you. You may need to pursue guardianship...but if i were you I'd start digging through the mounds.