http://m.ebay.com/itm/BG01-purse-metal-chain-strap-replacement-gold-crossbody-shoulder-strap-handbag-/111575873614?var=&hash=item19fa70b84e:m:mPYIxuUku25HHQ91CILiung&_trkparms=pageci%3Aa155d3f8-6848-11e7-b72b-74dbd180d6ec%7Cparentrq%3A3f3f05aa15d0a9c0b92b00d0ffea9d77%7Ciid%3A1&varId=410571759064
I have the BG02 rolo chain from them, great quality, super fast shipping. I received my order 6 days from purchase(I live in CA). It's less than $15 and if you only wanted a clasp on one side, you could easily cut the chain to the correct length and attach it with the ring already included on the chain.( Hope that makes sence)
I recently just bought the Pochette nm and I'm considering buying one of these chains from rebirthday or mcraft to use it as a crossbody. I noticed your pictures and wanted to ask how is the chain working out for you? They come in 125cm but I'm afraid it may be too long and the bag will sit too low on my body!