JCB3CX stalled under hydraulic load and will not start

[Spancan]

EUREKA I’ve got it started. I now have a clean sediment bowl, a clean lift pump filter, and a clean filter in the back plate of the CAV dpa injector pump. Thanks guys for all your advice ! However, I noticed that the fuel line between the lift pump and main diesel filter is joined with a plastic pipe (see pic) and is leaking slightly. Hence air may have been drawn in here. Will replace.
Also I notice that the engine oil is on the lower level of dip stick. What engine oil would I put in to top up (1982 JCB3CX White Cab Perkins Engine) ?? Confused by manual’ recommendation (see pic).

[gecko.cx]

What engine oil would I put in to top up (1982 JCB3CX White Cab Perkins Engine) ??

Any reputable brand of 10W/30 would be perfect for the UK.

[Spancan]

Would this be ok, as I will most probably change oil and filter.

[gecko.cx]

https://www.ebay.co.uk/itm/291610378035
It's a 'house brand' so it's hard to know what is in it, so I'll reserve judgment.
You could ask them!

Realistically, any suitable spec. oil you can buy now is probably better than what was available in 1984 when your machine left the factory!