As a registrar I never issued a single "historical" certificate, although the original registers were held in the building just a few yards away, nor did my Supt. Registrar as far as I'm aware. Although the responsibility lies with them it just isn't part of the role they actually perform.
All issuing of certificates, other than those from registers still in active use (effectively less than about 3 months old) were done by admin staff, usually those also managing the reception/appointment booking role. I'm sure any applications sent in will be actioned as soon as they can given the reduced staffing levels at the moment (there is no time limit stated in the legislation, as far as I'm aware).
