I suppose I should have guessed that anything to do with caravans is not straightforward.
To those of you who used AI - don't in future

It was wrong and ambiguous
It may seem that its not absolutely important about the profile as long as both are the same but what I want to avoid is getting something that's different from what I already have. Why - because if its different I'll have to reset the position of my motor mover.
The difference between 80 an 70 % profile on a 175 tyre is about 18mm.
I did some more careful measuring this morning and I'm convinced that the profile is 80%
I also searched for tyres with just the rating of 175/R14C 99/98 R and while these are available to order on line I haven't found anyone who will deliver to the boonies where I live. Interestingly there were some on Ebay but with a manufacturers date of 2020.
Also when seraching for the 175/R14C, some places offered a 175/65 14. So care is needed when ordering.
I still haven't found anywhere that states that without a profile figure the assumption is 80%.
I may just dump the problem on my local garage.