Hi there Tea
The vet wasn't sure what caused the paralysis, but she had a huge tick load just after calving, so there could have been some in that lot, though they were mostly cattle ticks. I have just come in, and she got up for only the second time just now, so I'm hoping that she continues to improve.
I am already running late, but am going to a seminar today in Yandina and the place I am going to may know something about ash, so I will make enquiries and check back later today. There is a wide variety of different timbers around here (I have LOTS of hardwood, but that possibly isn't suitable). Anyway, it's a project with some practical value, so I'll give it a go.