The samething happened to me... 26 years ago I got cerified with NAUI,, after not diving for years And there was No online records there was no such thing as Me! and who knows whatever happened to my card, So I went to the local dive shop to enquire, and was told the only way to make this right is to take the whole course, so I did, It was a NAUI O/W course which is the 1 they offered at the time and there was a PADI course too but wanting to get back into this sport the NAUI course was sonner,, so I stayed with NAUI and inquiring the differences as O/W theyre both recognized and they are similar I was told! So to me it is a matter of choice.