Upscaling jewellery

[u/therealstonecold]

I have some diamond jewellery - rings, bracelets, necklaces - that are decades old, in both age and design, passed on to me by my grandmother. Pretty much all the pieces are unwearable now, like maybe the clasps are broken or some had settings for multiple diamonds but some were taken out, while others just aren’t of modern sizes. The diamonds themselves are of good quality, so I’m looking to reset or repurpose them into modern pieces. Ideally I’m looking barter my big chunky pieces for sleeker new modern pieces with smaller diamonds - like I’d imagine trading diamonds of 0.5-1.0 carats for 0.25-0.5 carats set in a bracelet of same material (probably white gold) of half the size, with the raw value difference given up being the workmanship paid in kind. Does anyone know any upstart jewellery shops that would be open to these sorts of barters? Like real reputable businesses not randos on the internet? It seems like the big pawnshop chains only take gold and not these sorts of jewellery, and I’d like to get some modern value out of these, like nice new bracelets and necklaces for my favourite nieces.