i put an ID question in the main cactus chat which probably isn't the best place to put it
https://garden.org/thread/view...
@Stush2019 very helpfully came up with Cereus peruvianus as a possible ID for the second plant.
does anyone have a view on the first? or can confirm mammillaria polythele f. nuda
thanks guys
and sorry for the double post
Steve

I think the cactus may be this plant, or something close to it



and I would expect a stronger result on the Mammillaria if you can share a photo showing the spines and tubercles in more detail.