'Hi Kelly' is a well known song/phrase denoting manxmen (dates I think from c.1880's and then later via a music hall song).
The joke re boots is normally presented as a 3-legged manxmen in front of an amazed bootblack 'what have you never seen a manxman before?'
(There is a very attractive female version that appeared on cover of the 1901 Manxman magazine - can supply if you want).
But Kelly's boot I'm not sure about