The trailer (made by Eiri, BTW) is 40 something years old, parts may not be available any more, and I've seen different components in otherwise similar trailers. Axles, wheelhubs, brake components and drawbar are pretty easy to replace with new off-the-shelf components, they are just attached with few bolts to glasfibre shell of the trailer. I had this done for bit over 1000 euros in professional shop few years back.