Tony,
That is excellent.
How about increasing the weight until the 5 strands break and confirm that it is over 100kg but less than 125kg.
Also it would be good to measure stretch, but I think double checking the breaking strain of the 5 would be great.

I would have some weights if you need them.
Interesting stuff.

Regards,
Phill

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!