If your m/e rating has been expired more than 12 months you will need to do same test as for initial rating issue
I don't believe that is so! Its only the ME bit of his IR that is not current!
elcap
I have been in a similar position to you. For the last couple of years I have only renewed to SEIR as I do 99.9% of my flying in the Bonanza and have no reason to bother with ME at the moment.
If your SEIR is current ( or if you do a SEIR renewal) you should only be required to do the following additionally in a multi-engined aircraft:
1) EFATO (Edit: Engine Failure After Take-off - under the hood, obviously)
2) Asymmetric approach (or engine failure in the approach) and missed approach - on one aid only!
I guess if they want to really give you a workout you might be asked to demonstrate asymmetric circling once visual.
Dr 
PS: Sorry - I can't give you references for the above - but talk to an experienced IR instructor who is not just interested in relieving you of as much cash as possible.