Step needed for a trailer any ideas ???

[brough74]

My father in law who is getting on a bit (74) currently transports his quad around on an Ifor williams euro light trailer (wheels underneath), and uses a pair of ramps to get it on and off the only downside is that the trailer is only about 6" wider than the bike. So he struggles to get down the side after an issue with his leg, so i was thinking of a fold out step or something bolted underneath, near the wheel. Then it would be out of the way when its not required thus keeping the trailer narrow.

But im struggling to find something suitible as it needs to be about 16"- 18" long when folded out and it would be better if it locked in position.

So has any one any ideas or links to products ideally in the UK