Sterling Silver Tea Service 1931??

Hi, I am trying to find out if a sterling silver tea service is worth selling. It has been in our loft for about 15 years but has been used previously. It consists of a teapot with wooden handle, sugar bowl and milk 'cream jug. I’ve been unable to effectively capture the hallmarks on camera but they consist of HW/Crown/Lion Passant/o. I think this means from Sheffield/ Sterling silver and about 1931 but as I’m unsure whether the o is lowercase or capital. It might be a completely different date. Anyone any ideas how you can tell? It is all in good order. No repairs and only slight knocks/dents which I think you might expect. The hallmark is also on the inside rim of lid of teapot. I would welcome any information about this set and also if it is worth selling. If so how do I go about it or should I just put them back in the loft?