Well Ive always thought of them as "lookie lookie" men and to be honest I think of them as separate from the "scratchcard touts" in that they dont bother me - I sort of see them as part of the holiday now! - to me they are the guys walking around with armfuls of watches, sunglasses and general tat!
I agree, Lookie lookie men are a completely different species than the cucarachas that walk around with scratch cards.
I always thought that the term came from the accent of these street traders ( whether they be legal or illegal is irrelevant) their 'African accent' when trying to speak English turn the words 'look here" into one word.
They were so desperate for a sale, and to either catch your attention or keep your attention, they would ALL say " look here" it seemed like they had all learnt just those two words.
The "here" bit got tagged onto the word "look"...it came out as something like loooook eer, with the 'here' bit not pronounced correctly and to the European ear sounds like lookie.
Hard to explain in the written word, but orally I could get it over what I mean.
How it got from 'lookie' to 'lucky' I think that is just the mishearing of the word lookie and being interpreted as lucky.
Sanji