CAP 804 isn't in force until the 1st July isn't it?
From Lasors:
If revalidating by flying experience, and providing
the examiner signs the Certificate of Revalidation
page within the 3 months prior to the rating expiry,
the validity of the revalidated rating will be calculated
from the date of expiry of the preceding rating.
Whopity - so if an FE signs it off before the 3 month, they use that signing date as the renewal date, otherwise they use the expiry date of the SEP?
Important Note: If intending to revalidate by flying experience, the Certificate of Revalidation must be signed before the expiry date of the previous rating has passed, otherwise the SEP/TMG rating renewal requirements of F1.5 will apply.
So unless Whopity can shed any light on it, according to LASORS, Msl3, you're out of luck unless you can get it signed off tonight.