Other Identifying Source of Trialer Parts

Hello All, I hope it's OK to talk about a trialer (ruddy auto correct keeps changing that!!) in this section, I'm told most of the parts came from a Range Rover! That's the key to my question really, I'm in the process of buying an off road trailer to enable me to enter club CCV competitions, it will come with an ALRC log book but to help me get manuals and eventually parts I'd like to understand where the components came from. Assuming I can find the relevant engine / chassis / axle / gear box numbers, is there a way of identifying the vehicle they originate from? Thanks in advance. Richard

There are different Range rovers pictures to aid identity would be good.