Cambrian Railways Seaham tank details

[NCB]

I'm in the process of building one of the Cambrian's Seaham Class tanks, in the form rebuilt by Aston, as running in the early 1900s. I'm having trouble with details of the bunker, which lay within the cab, two things in particular:

 

1) Was the top of the bunker totally open, or was it partially closed, at the ends. Engines with in-cab bunkers seemed to have had either.

 

2) Wondering what the front of the bunker looked like. Presumably it would have had some sort of opening, to allow coal to be shovelled out, possibly with some form of door.

 

Any ideas gratefully received!

 

Nigel