Hello! I will sort some pictures asap. With some minor mods you could extend it. I will get more info asap. If my memory serves me right it's 2500kg rated.
Please excuse the lack of information but I done it at work.
The boat currently on it is 20' long and the stand post is about as far forward it can go and the keel is supported fully
Give Graham a call and he may be able to answer most of your questions.