I believe they are lot 17 or 18. Samurai website states the 512xxbc is a high rise slim fit. Being unsanforized I’m thinking a38 would still shrink too much. But a 40 seems like I would be asking for a poor fit in the waist. The s5000xx25oz claims to be a mid rise and is as low as I can go. As stated before I got them on eBay used for just under 200usd so I can deal with it on this pair. Maybe I could go with size 40 512 and if they are too big have caino farmer size them for me?