The cat crawled into a previously unaccessible small space & I was really worried,

[KatyMac]

but I got out some ham and he climbed out again, ate it all and went to clean himself on the sofa - talk about relief

cats can squash into some amazingly small places

Yep - but they also go into small spaces to die & he is very old

Nope - he has crawled back into aformentioned small space - I m worried again

how is he now?

He keeps coming out & then going back in again - I a guessing he has just found a new warm spot

Panic over (I think)

yes in an old apartment my cat as a kitten used to squeeze through a gap behind out cupboards and crap behind the cooker

No he def isn't poo'ing there

i always thought they went away to die? i wouldnt worry about him like you said it is probably just a new warm space