Did a little digging about and so far looks like its a go'er!
these are a pair of coilover shockers form a mini (classic mini)
And here is a HA front one
I had a natter with Bulldog last night and got him to messure some mini ones and fully closed they are 12", guess what so is a viva HA one, the top fitting is the same, and the bottom bush should be similar
The idea from the NSRA was to leave the existing leaf spring in place and shove in some coilovers.
get yourself some mini van rear coilover shocks they fitted straight in to the same space as the old shocks works a treat as well ,ive left the leaf sping in there as i got told if you take it out no.1 they are a **** to get out and no2 the leaf acts like a cross member so when you take the leaf out the bottom arms tend to woble about a bit
Thoughts welcome