Cheers, folks.
Glen, the main wood texture, for now, is plain old fractals. I think I'd need to create some kind of warped sine to plan side-on to the desired surface. I hadn't actually thought of the end grains at all yet, I've been keeping my attention to functional masking of separate shaders to apply to a single surface until now. I'll see what this looks like on the end grain, I might be pleasantly surprised.
If not, though, I'll keep this in mind and have a go later on, a good point, that I hadn't considered, cheers!