Barney,
You don't need to be unrestricted to instruct IMC: <a href="http://www.ais.org.uk/uk_aip/pdf/aic/4W369.PDF" target="_blank">http://www.ais.org.uk/uk_aip/pdf/aic/4W369.PDF</a>
Basically:
[quote] For an IMC instructors rating you need 50 hours IFR, IMC rating and complete a course with an FIC instructor, 5 hours flying and 35 hours ground,realistically it will usually take more than 5 hours cos of all the course teaching, e.g. G.H.full and ltd. panel, NDB hold, ILS, RADAR APPROACH, VOR tracking, HOLDING procedures, you also need to pass the flight test. <hr></blockquote>