As you say you are a collector, I thought you may like to know how I got the SoM.
I bought it from a farm that had no grid supply until about 1990.and when I started to rebuild it I found that I needed far more parts than anticipated.
I looked around locally and found someone who had put together a bunch of generators on the St Marys and the off islands of the Isles of Scilly in 1985ish when the islands had a cable laid the 21 miles from the mainland. These engines were brought over as a special shipment on the Scisolian.
I found that shipper and his haul of loot in a big shed that he would not even let me peek into. He asked me what I wanted, went in and locked the door. When he emerged with the goods I could see that it was very much a sellers market and I had to pay his prices. Anyway, I rebuilt it all with the help of David Harris who was retired and used to work at Listers, Dursley. He was supplying original manuals and was able to date engines but he has sadly died now.  Chris.

I have a six horsepower Lister CS that I found outside. I suppose you could call it a field find.
 I have one myself, a Lister 8-1 S-O-M.  and would like to pass this one on to anyone prepared for some considerable work and expense.
It has been in my shed for 16 years. There are parts missing and it needs lots more replacing.
The photo shows that. If you are interested please P.M. me for more details. Chris.