Hi Topi,
The Nicopress are ok with 7x19 because of the surface texture they swage into ie much more little cavities to give the grip needed to exceed the breaking value of the cable.
If you use that system on 1x19 it will fail (cable will slip out) before the cable will break.
The original Top Hat had 3/4" gal 1x19 but that is a circumference measurement so equal to about 1/4" diameter. Gal is not as strong as S/S and the original was for off shore use.
Many Top Hats are rigged 3/16" S/S but that is not for off shore.
I rigged with 7/32" S/S which is probably overkill for the shrouds but about right for the stays.
White Tie was rigged with that size for the Trans Tasman in "78 and she stood up ok!
Cheers,
Tom