Plastic inner wheel arches on ‘85 90?

Our pre-Defender 90 probably has the original front inner wheel arches… at least that would explain the state of them!

I’m wondering if it’s worth trying to patch them up or better to just replace them.

Does anyone know if the more recent plastic arches - LR053803 I think - would be a drop-in replacement? Interweb shopping sites seem to think they’re for 2007- Defenders, but one or two places suggest they’d be OK on older (in our case much older) models.

I'm sure I've read a post on here of someone who has done that and I don't recall any issues.. maybe try a search?