The CAA provide a document so you can look it up for yourself
http://www.caa.co.uk/docs/175/Sectio...%20RATINGS.pdf Page 9 (RENEWAL).
Test + Seminar within 12 month period. If rating expired by more that 5 years send to issuing authority to have it re-issued. Other ICAO rating has no relevance. If its well over 5 years additional training may be required, also, if FI rating completed in another JAA State it would be advisable to ensure you are in tune with way its done in the State where you are being tested (They can be quite different)
FI Test fee currently £200 in the UK.