in www.manxnotebook.com/fulltext/ds1918/dukest.htm there is a poetical description of duke st
By Lemon Brothers, enterprising Jews,
With jewellery and all that accrues,
Which vanished in a most destructive blaze,
Then vanished they as well and went their ways;
Mem’ry recalls their youthful brother Sam,
Though but a Lemon, just as sweet as jam,
Well known among the Douglas youth as " Punch,"
Though destitute of that street-hero’s hunch.
Across we find a Sixpenny Bazaar,
With goods and ornaments from near and far,
But chiefly useful to the good housewife
With scanty pittance in these days of strife.

If they were Jews then this would explain some problems in traceing them