I’m very much a lurker on here - so apologies for my only post being a sales post, but it seems highly likely a Soundplane is relevant to someone’s interests around here 
. I have done many trades on lines, elektronauts, muffs, etc.
£1400 - UK/EU delivery included
The Soundplane Model A is in great, fully working condition.
Unfortunately the Soundplane was slightly damaged when it was shipped to me (the person I purchased it from did not pack it very well) - however the damage was only cosmetic and I had it repaired by a local luthier. See nelsonlukeferryman.com/soundplane for more details & photos.