The racing rules now specify it; vinyl traps the water and masks the corrosion going on underneath. I would replace 1983 lifelines sooner rather than later.

I redid mine last year, using 3/16 1x19 wire and Suncor Quick attach fittings from Defender. It was relatively easy and came out very nicely. I did away with turnbuckles, and instead used an eye and light Spectra lashing for simplicity. I strongly considered using one of the new high-tech lines but in the end stayed with wire. If you search there have been some good discussions in the past (not sure of the search is working well right now though).

Max