Preserving an elder stump with roots

Hi all,

Through the virtue of my step-father renovating his garden, I’ve recently become the owner of this rather handsome elder tree stump, complete with gnarly roots and interesting cavities.

I’d quite like to preserve as is, and get it to a state that once the lockdown is lifted I can bring it down to the space and do something arty with it - maybe make it into a cool lamp or something.

I’ve never taken on a project like this, certainly not with unseasoned timber, so looking for any advice as to how I should clean it, treat it and seal it. I’ve managed to removed most of the dirt from the interior, but there are lots of nooks and crannies created by the woodlice that will need properly cleaning. The interior wood is also very soft in places, so wondering whether I should scrape this back too.

Any advice gratefully received!

Thanks,
Josh