No, am afraid case receipt number alone is not enough. The actual I-140 approval notice on Form I-797 must be attached to the the new H-1B petition. You will then get an approval for 3 more years (if your new H-1b will be deemed approvable on its merits.
If current employer will end up revoking the I-140 you'll have nothing to worry about, as long as your new EMPLOYER'S H-1B petition goes through and is quickly approved, which will give you 3 more H-1B years. The fact that the I-140 will later be revoked wont change that. You will then have the new employer file a new PERM on your behalf and can claim the first PERM's priority date .
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.