They've been around a long while. Over 20 years at least. They are easily recognisable as a design, so they should know what they are doing by now. We bought a secondhand stud box that they'd built. It was good value for money then and sold on again fairly easily. But this was 15 to 10 years ago.
4 years ago we bought an oldish hunting box off a Winterbourne owner. Definitely a well made box. Took it down to Spain and back a couple of times. When we needed to sell it again Winterbourne were happy to sell it from their forecourt on our behalf. Since Bournemouth and Winterbourne boxes are of a similar overall design and their premises are only about 15 miles apart, if that, you may like to check both types out in one go.
We'd happily buy either type again if the need arose.
My box is a Bournemouth horsebox. I bought it second hand and i love it. Its old - 1990 H reg but really solid . The chap who owns the business is really nice and easy to deal with.