Thank You All for your advice. Damn, I love this forum!
I have been rather busy getting my old 84 Hobie 16 ready for our upcoming holidays.
The hulls were leaking and one pretty bad, so did a bottom job on both hulls just need to sand and paint the last one and they should be good to go.
I manged to take the mast head off, wasn't to much of a issue. But will drain and give the mast a good going over on my return.
Will be taking my original mast and the now loose spare masthead and main halyard as backup.
The masthead pulley on my original is looking rather brittle and has a few cracks around its edge.
Indeed the other week when taking down the mainsail the halyard wire line some how slipped between the masthead pulley and the masthead casting it was jammed so tight it took a heck of a job to release it, with the risk in stating the obvious it required lowing the mast. Hey Ho!
Thanks Again Folks