The OEM Lock is, as far as I know, not able to be opened without the corresponding offline file.
Its purpose was to prevent access to protect Intellectual Property Rights, and I don't think even RA can get access to it. If they could, you would have to prove to them 100% (possibly 110%) that you have the rights to access the program.
But it can be a headache when an OEM goes out of business, which basically means the "key" is thrown away.