vw Clubman GL Battery tray rotten

Anyone give advice as to where i can purchase a replacement battery tray for the above 1998,surprised to find they were made of wood,or has this already been replaced using wood as an easier alternative?

Sounds like it's been rotting for a while and the previous owner was used wood to support the battery - of course, whatever made the original tray rot would also rot the wood and make the whole area a bit rusty..................