Peter,
I recently got a new set of trunks & fittings (70mm dia) from Humber for £25 ea +P&P. It's a touch more if you go for the full kit with string, bobble & cleat, but if you already have that on board...... They can make them to any length in pretty much any colour they make their boats.
They also do 150M dia, no idea of the price tho'.
Their tel is 01482 226100
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