Over the years there have been many posts from users fretting over oil temps, water temps, oil filters etc etc etc. It is important for a user to remember two things. One, the reputation these engines have was built upon them used as shipped and operated with cool water jacket temps, cool old temps, inferior oil quality etc. And 2, A CS is an entirely different operation than a modern diesel and one should not universally apply modern engine wants and needs to the old CS.

I know of one CS that has pumped domestic water for as long as anyone alive can remember, not 24/7 of course but runs every day. it has a flow through cooling system thus it never gets luke warm and knowing who owns it id guess oil change intervals are measured in decades,, if ever. Moral of story is there is no need to over think a CS engine installation.

Those are a #6 taper pin.  In the states I buy them from McMasrter Carr

Edit,
I am pretty sure they are #6 but don't rush to buy until I double check that

I agree with Cobbadog. On every Lister of that vintage the fittings, meaning plugs, taps, even some of the tube nuts are BSP. If set up for a sealing washer there will be an area machined flat around the threads and the tap will need BSPP threads and you need a seal washer. More likely it uses the tapered version or BSPT.

Hi again, I run a very low profile operation. My email is on here or PM for phone number. The 10HP versions came in at least two bore sizes. 120MM and 127MM Head gaskets for all bore sizes are in stock, rings for most bore sizes in stock. The common valves are in stock as are all bearings, seals etc along with many major pieces, castings etc. Your stocking needs will vary with planned hours. 

Hmmm, I can't explain that either? He still advertises his buisiness at quite a few old engine sites?  I contacted John late in September and ordered 50 headgaskets for CS type 114.4 MM bore and 120mm India clones. He said no problem and 3 weeks they were here.

Just bought quite a few 114.5mm  and 120MM bore head gaskets from them last month.  I think then O P was referring to the old cyber store that John's sister ran.

Soon to be completed 6/1 Lister for sale. Should be done late year. Total disassembly, corrected in every way possible way and assembled per Lister technical data sheet per new engine specifications, NOT wear tolerances.  New hard valve seats, new Lister valves,  reground crank, best quality bronze back rod bearing. Both ends of rod reconditioned, new iron piston, good Listard chrome bore etc, etc. Too much new to go on listing. Price finalized when completed, estimated price cheerfully offered via PM. 
 With  7 CS types and roids through the shop just his year, we know these engines and do them right,, or not at all

I don't have the figures but back when I was learning how to balance one of these engines I checked the off set weight in a Lister 6/1 spoked flywheel vs an 8/1 disk type and there was definately less offset weight in the 8/1 flywheel.  That being said a 6/1 with spoked flywheels will run very smoothly with an aluminum piston at 650 RPM but dereriates quickly above that.