Jim
the topic is IMHO not a wise one to raise on this board - (a) majority of readers are not Manx or have had anything to do with the Island for 2 generations or more. They are rightly proud of Manx descent but view the Island, I suspect, via extrememly rose-tinted spectacles of ignorance (you can tell their degree of ignorance eg by the direct quote of the IoM England tag) - their forebears left in general for one simple, compelling and depressing reason - there were no jobs. This situation continued until about the 1970's at which time the Manx Government first introduced a new settlers' programme and also initiated the off-shore finance sector. This latter has succeeded (a) in bringing unheard of wealth (b) full employment & (c) a situation in which over 50% of the Island's population are not manx born (as for axample is myself). These Finance Sector 'come-overs' have provoked much discussion (to put it mildly) - there are many (but not I think any where near a majority) who wish to return to the '60's when housing was cheap, jobs scarce and the come-overs went back-over on the morning boat - the Manx Nationalist party has a sanitised version of this as its policy.
Re Manx Gaelic - it died c.1820; by 1875 only the over 50's had a working knowledge; by 1900 a few tried to revise it - neoManx was resurected (this statement is contentious) c. 1970 partly I believe as a result of the new settler program and the view of some that their heritage was about to disappear.
The Manx are like the English very much a mongrel race - there have been come-overs from the Irish gael/Norse c. 900, Lancashire people from c.1400 and many more besides - but all Nations need myths - that of a Norse past is one
Now quite likely most readers will have some view of the Island, that the Manx seldom go in for retrospection has been noted by many - there was an interesting paper at the 'Small Islands' Conference' some 3 years ago on this lack - possibly one book is the photographic essay of the 1960's before the major changes of today kicked in