G'day, It was easier than I thought. I picked a ARISTO T12 head a while ago and wanted to fit it to my early model Durst L184. I first looked and then removed the old light chamber. I then placed some square alloy to space it out. This looked OK. I then looked at the 4 bolts at the back of the head (where it connects to the focus and adjust area). I removed to condenser head completely. I then went to the local engineer and had the weld a piece of 70mm x 300mm x 1mm to a piece of 40mm angle, (stainless used throughout). This allowed me to place mounting bolts into the aritso head above the tube area and meant I didn't have to use a wide piece of angle. I placed 4 holes in the back of the angle to allow it to mount where the orginal condenser bolts were. The negative carrier is OK and it looks a heap better. I now will fold up some colourbond steel to fit over the back where the focus rods are. If anybody want the information send me a PM or try me on SYKPE as the same name here (largeformat_pat). Hope this helps I took pictures as I went.