unfortuneately that won't work - it is those that fall through the cracks that are interesting.

The 1911 transcription was microfilmed - see my site for film details, this was then transcribed, often incorrectly, to form basis of manx IGI to which much other 'junk' has accreted. The simple task is probably recovery of the 1911 transcription - this forms the basis of the Civil Registry's database pre 1877. Call this stage 1 - the data is not complete nor 100% accurate but better than the present 'pot luck' in the IGI.
All the old Parish Registers are now in Manx Museum - many were actually microfilmed by the Mormons - those could provide a check on the 1911 transcription + add a few details that were included in that transcription - mostly witnesses and other details of marriages - this is stage 2.
Stage 3 is the addition of 'missing' records available via Bishop's transcripts - I think these are manx Museum only.
Stage 4 (tho not necs sequential) is the determination of illegitimate births as these are 'misnamed' by IGI
Stage 5 is the remaining Catholic records - these have been transcribed and presented to IoMFHS but should be made more widely available than sitting in a filing cabinet.