I'm tempted to just have the IMCr added pronto (although I think I need my licence for the medical so will have to check that point as it would leave very little time to have the rating added & licence back by 13 April)
You shouldn't have to send your (JAR-FCL) licence with the IMCR application - see last page of the application form:
http://www.caa.co.uk/docs/33/SRG1125FF.pdf
Think I'll give them a chaser call