After a bit more research, it would seem that this bridge is slightly adjustable. This version is set at 18+/-1.5mm. However, the same model is available with 19mm (or even 21mm!) spacing. I guess it would be a straight swap. If you picked one up second hand and sold the existing bridge, it would only cost a few quid...
https://hipshotproducts.com/products/5-string-a-style-bass-bridge?variant=31567451400
You're welcome 😎😆