The wires are still more than 10 years old.
I would at least do a thorough rig inspection - it can be done from a bosuns chair with the mast up.
Loosing the mast will cost you much more than fixing it up front..
If it was my boat I would have ripped those mast steps off...
If you decide to keep them with the "anti foul halyard kits" installed you should look at another way to solve the attachment.
Seems a bad idea to drill large holes through the new spreaders.
Where I keep the boat we have a mast crane that can be used by members of the club who have done the training class for mast crane operation.
So for me the cost of taking the mast off/on = 0$
It's not difficult to take the mast down if you have access to a suitable crane.
You can get lots of useful info here http://www.seldenmast.com/_download....=595-540-E.pdf
Most of this applies to all masts even if this is from Selden
As I already said - having the mast come down is even more costly (and dangerous).
If money is an issue I would have considered to make new spreader(s) in wood (if I could get hold of materials at a reasonable cost).
Are you mast keel or deck stepped?