Check this out, Martin Hannett's actual very own International 4600 Synthesiser. It sold pretty quickly...
"Martin Hannett's ( Joy Division producer and many Manchester and Factory bands producer, he played synths on many Factory records) actual International 4600 analog patchable synth . Not much needed to restore as cosmetically it is all there and the keyboard was triggering synth sounds recently, but sold as complete restoration project. comes with Martin Hannett's build and instruction manual from 1977/78/79/80 and copy of his patch notes. A much tattier one of these recently sold non working for around £1000 without it having any Martin Hannett ownership.so its a snip at £1400 with all the Hannett related historyThis one has metal protective edging. If you are in the UK would still ship in foam and a crate or you can collect. Will ship anywhere in the word but would crate it up to ship"
UPDATE: And now they have listed Hannett's Transcendant synth and Revox tape machine! at £6K its not cheap though
"Working Transcendent analog synth 1978/79(with documentation) used and owned by Martin Hannett ( he owned two of these) Transcendents were actually used on Joy Division, Durutti Column and lots of Factory and Manchester band recordings and Hannett often had one in the control room as well as the band having one in the studio area. This includes his instruction manual and handwritten mods he did to the synth. We know the Transcendent was used as a straight synth sound and also used to feed triggers from sound sources into it on many Hannett recordings. There are several photos of Hannett using Transcendents around 78/79. Also included is one of four of Hannett's Revox mastering machines that he would take one to studios to make copies of his mixes each day and he had them at home too to listen to his studio work on his home hi fi system. This Hannett RevoxB77 powers up but needs attention. these are important Hannett and Joy Division related artefacts and will climb in value as fascination with Martin Hannett continues to grow"