ME IR for £300 is a good price. I paid slightly more in Stapleford 18 months ago, but was well impressed with their training.
None of the airlines I worked for even bothered looking at the bit of paper, so may I suggest you only get the IR, not the CR. Maybe even let the whole thing lapse til you get an interview, as the renewal shouldn't take more than two days to renew.
If I remember correctly, you do exactly same training / test, if lapsed up to 6 months, training "as deemed adequate by the authority" if lapsed more than 6 months. - usually 5 hours including test, which is probably what you'd need anyway after such a length of time.
I can assure you, from my experience, that an employer is not interested wether you can fly a small twin engine prop, given that you can fly it in IMC.
hope that helps, IP