OEC, OMC, Antique Cushion for Diamonds by Lauren Setting

[Leda]

Hello! I am a longtime lurker and excited to finally post (and indulge my newfound love of old cuts). I have an 18k yellow gold Diamonds by Lauren setting which I would like to set with an Antique Cushion, OMC or OEC, as well as an 18k white gold Whiteflash Butterflies setting which I would like to reset with two ~5.3mm side stones. I will be attending InterGem in San Mateo, CA next weekend and I'm hoping it'll be a good place to start my search. I am looking for an approximately 5x5mm stone and most prefer the K-L-M color range for the yellow gold setting (and a bit higher for the white gold setting). I have taken a look at OldWorldDiamonds but am frankly a little lost. I'm open to buying pre-owned pieces on eBay and the like as well and am hoping you would be so kind as to recommend reputable sellers. I would appreciate any help you might offer. I have been soaking in all the information I could find on round brilliants for some time, only to find I prefer old cuts, and I could use a nudge in the right direction.

 

[foxinsox]

Ooh welcome to old cuts! My favourites! What’s your budget? Ok so I would look at Ivy and Rose Vintage, Love Affair Diamonds, Jewels By Grace and honestly do try reaching out to Adam at Old World Diamonds cos he’s got SO many stones and by all accounts he’s the nicest man.
Do you know what shape/facet pattern you prefer? Can you post pictures of the settings you have?

 

[EC8]

Welcome to the old cut club!
From past experience of retro fitting a stone in an existing setting, the new stone has to be pretty similar in size to the previous one i.e. within a few tenths of a millimeter, so having that information will help guide your selection.
My recommendation would be to go to the show and try to look at as many stones as you can to see which, as @foxinsox mentioned, shape & facet patterns appeal to you most. I started out thinking I wanted an ACC but ended up with an OEC.
Re color, again, the more you see the better you will be able to tell what you preference/tolerance is; although I will say, cut will have a big impact on the face up color - my OEC is an M but faces up quite white so I was able to go with a platinum setting.
Lastly, having worked with Adam @OWD personally, I highly recommend him, he's got a large inventory of antique stones, an eye for picking out well cut ones and is so easy to work with!
Good luck with your projects, looking forward to seeing updates.