Ah, I thought by 'more homely' you meant some nice lace curtains, a fireplace and three ducks across the windscreen. Thinking about it, a fireplace wouldn't be such a bad idea considering how good the heaters are! Yes, I saw 90/110 leather seats advertised on EBay recently, I think they were from a special edition. Nothing to stop you having the existing ones re-covered in leather, I expect any decent upholsterer could do it - for a price. Carpeting should be easy enough, get something 'suitable for the purpose' from a car trimming shop (search the web) or if you want a nice piece of Wilton for that really homely feel, go to a carpet shop and buy an offcut and some double sided sticky tape. Or.. stick some carpet (with Evo-Stik) to some bits of plywood. You can then take them out when you take garden rubbish to the tip, or whatever. For one 90 I made a simple 12mm plywood platform which extended across the rear tub, sitting on each wheelarch and covered it in carpet. This gave me a good storage area under it and also cut down on noise.. It also made things left on top easier to reach from the front seats.. You could mount speakers above the windows either side of the back door. The cables can be run up behind the 'A' pillar' trim (either side of the windscreen) from the dash and along the roof/side panels channel - where the roof bolts to the top of the side panels (out of sight). Easy enough, just a matter of finding the right speakers..