Where to find a narrow bath?

[CheeseBadger]

Simple one really. We'd like to move the bath when we refurbish the bathroom, but the logical place for it only has space for a 650mm(ish) wide bath. 700mm seems to be a really common / standard width, but I can't seem to find anything narrower. Length is not an issue.

Having spent most of this New Year's time off searching, I've found one that's 630mm wide and was made in the mid-1920s. Do I really only have a "choice" of one bath?

I blame the obesity epidemic...

aquabliss.co.uk/fortuna-600mm-single-bath-shower-screen?gclid=Cj0KCQiAvrfSBRC2ARIsAFumcm_Pu73KPIQtKU_M70RShtVZC6NdiPfUIlo1p4Qqzr4ppk672wt6nLwaAjRSEALw_wcB

Something like this ?

Sort of, but I need a bath, not a bath screen. We were hoping to avoid acrylic too, as it needs to last for possibly 40 years...

www.sanctuary-bathrooms.co.uk/pura-essence-1500mm-freestanding-bath/
This ? Not sure if it will last 40 years

Found one here. Needs to be rectangular and not freestanding due to the severe lack of space. Might go for the 90 year old option anyway. Anyone know about the perils or otherwise of cast iron baths on suspended timber floors?