Maximum mass of a motorbike trailer

[mat777]

I am looking to get a small motorbike trailer and modify it with a flat floor and collapsible box body for transporting my traction engine (annoyingly its 10" too long to fit in the land rover)

I have spooted this on ebay and it is only 3 miles from me:
http://www.ebay.co.uk/itm/SINGLE-MOTORCYCLE-TRAILE...

however, the seller does not know what the MAM (maximum authorised mass) of the trailer is and apparently the data plate is missing/never had one. Now, allowing for a safety factor I need a trailer with a 350kg MAM but I know most motorbikes weigh half that, hence the need to clarify if the trailer is strong enough.

Therefore, does anyone have a clue whether that traile would be strong enough? Also, is it possible to tell from the picture whether of not it has indespension units? I need one with some suspension to it.

thanks

matt