Interior hull finish

[Farjr]

I am finally getting to a 1961 Sea Skiff 23 restore/custom.....my question is.....did they varnish the whole interior of the hull? I know the ribs are the plywood planks show a possible sign but age and weatherin has subdued the finish. I want to scrubb her out and put my protective coat on before moving forward. Engine and tank will be coming out soon. Thanks