This will take you to Billy's ploughing engine build.
http://scalesteam.proboards.com/inde...play&thread=23
Its possible that 4" patterns are about as Station Road steam had a 4" K5 for sale, may be worth contacting them as he has sold several engines by the same builder and may be able to find out if the patterns exist.
http://www.stationroadsteam.com/stoc...2854/index.htm
I'm 95% likely to do a 2" Z7S or Superbra when my current engine is finished but will get castings from Blackgates, just too many reports of supply issues with Brunell.
Jason