foam boot inserts

[Tatunka49]

I have just bought a 2018 acenta premium 1.5cdi, well happy with it apart from no spare wheel only gunk. I have aquired a space saver with the tools but no foam spacers , have checked usual markets ,ebay, FB marketplace etc but cant find one at a sensible price ( its only foam after all) for this year and model ,can i doctor a j10 spacer to fit ,which seem to be more available at sensible prices.