Our 1970s Westerly Tiger has stainless steel safety rails/wires on
stanchions around the boat. At the attachment to the stern pulpit
each
steel wire is fastened by a now dodgy looking (probably rotting) rope
tie.

Wondering what is the reason for these:
Possible alternatives?
a) Easy to cut and release with a knife in an emergency?
b) To avoid having a metal 'loop' around the boat that 'might' affect
radio direction finding, if used, on the now old fashioned lower
frequencies, such as coastal beacons in the 'Long Wave' band or
broadcasting stations in the 'Medium Wave' or 'Broadcast; band.

Obvously of no concern for GPS!

Could one use a metal turnbuckle and/or quick to disconnect pelican
hook instead?

All suggestions and/or experiences welcomed. Thanks.