updated. in the meantime I installed and tested the fittings for a jump seat and used them for a few hours, despite the swell of waves that were sometimes 2m high, the fittings held up great. I'm very satisfied
Impeccable workmanship makes a very valuable impression the mechanics also makes a good impression. Although the holders are not yet in use (this should result in folding table) but I assume that the initially good impression remains.