Just wondering if anyone has used these on the side of there campers and jerry fit in there easily?
yes and ...not always!...
Mine are on an angle as that was the only way to fit on my trailer & clear my pole tubes
I ditched the top frame in favour of a strap - but then I use it for water, not petrol, so I doubt whether anyone would be inclined to nick it.
I have only used plastic jerrys, so can't comment on how metal ones fit.
Couple of things to note with these;
Depending on rigidity plastic jerrys often bulge when full - These holders are a very tight fit when full.
Being a tight fit, you need enough space above to withdraw the jerry to almost it's full length before angling it out, so this would preclude some spots on some trailers.
Not a good view of it, but here is a pic - I have one on each side.