1) Department can always issue Corrigendum to the show cause notice already issued.
Mistake in the show cause notices can be rectified before adjudication - CESTAT BANGALORE BENCH, Cauvery Iron and Steel (India) Ltd. v/s Commissioner of Central Excise, Hyderabad.
2) It is on recrod that the assessee is not registered under Manpower Supply Service not carrying out any such activites; but registered under Erection, Installation Service for which service tax is collected but not deposited. Hence, even without corrigendum, the show cause notice is valid and legal as it is issued for non-deposit of service tax collected and with reference to the Erection and Installation Service provided by assessee; who is not registered norcollected any service tax under Manpower Supply Service, hence it is nothing but a simple typing/clerical mistake, not having any bearing on the scn issued.
3) Instead of pointing to such mistakes, the consultant of the aseesee should guide him to pay up the service tax immediately and also inform the department about the typing mistake in the scn.
4) Section 74 also allows for rectification of mistakes, (though herein there are no such mistakes).
5) Income tax department should open assessment for tthe last 7 years period based on the scn issued to the assessee and without waiting for the outcome of the service tax order.