advice:
1/ there is no "ten year rule" - talk to your own insurance company
2/ assuming you decide to replace, you have 2 options - buy from a rigger or d i y
3/ d i y is easy for anyone competent enough to tighten a bolt.
use norsman or stalok fittings. buy the wire in one length. carefully cut to length (measure twice, cut once) and then fit the fastenings remembering first to fit any plastic tube over the shrouds.
the trick of fitting swageless terminals is to first slip the top part of the fitting over the wire, then unlay the outer strands so that they look rather like a flower. make sure they do not cross each other. then fit the cone to the inner stands. then with a twisting motion of the hand, relay all the outer strands over the cone, again making sure none are crossed. bolt the fitting up.
I used norseman fittings on the bottom only, had the tops swaged, its considerably cheaper, having the tops done this way, you can erect the mast, then cut the bottoms to suit and then fit the norseman terminals. However, as you are re-riiging, you know the lengths of the rigging, buy it all in one length, from a wire maker or wholesale, cut it to length, then get the ends swaged on, cheaper still than norseman terminals. There are several ways to skin a cat, with your question, I suspect you are about toi find out many different ways to rig a boat! All of the above, is if you are using stainless, galvanised is another subject entirely!