Bronze age British languages

Our recent discussion of Celtic languages has established that the word
order VSO is peculiar to Insular Celtic languages, while Continental Celtic
languages are typically SOV. This suggests that prior to adopting the use
of Celtic languages, the British may have spoken VSO languages, and adapted
the Celtic language to the syntax they were used to. Do we have any other
evidence of what these languages may have been like - for example, are
there words found in Insular Celtic that do not have cognates in other IE
languages? (If the older language was IE, it would probably be impossible
to recover, as we would need to compare Insular Celtic to Continental
Celtic to find the surviving terms, and Continental Celtic probably isn't
sufficiently well attested).

Pete