Mosin Handguard retainers

[dgreene]

I'm thinking of an experiment using the existing mosin 91-30 handguard retainer spacing to install a ching sling. Does anyone have experience with finn m39s with the retaining rings with the sling swivels which has a split and a screw to secure it? I'm wondering what size it is and if it might be close enough in size to the rear band to replace it to use as the center swivel mount. I can't find a measurement for it anywhere. After much work the rifle shoots amazingly (crown, pillars, floated, bedded, timney) even though I am using a cleaned up original stock but I've fallen for the Ching and want to see if I can make it work without screwing something modern into the rifle. Actually while I'm at it if someone knows the dimensions of the m39 type front retainer I could use that info too. The original stock was BEAT but the gun was amazing, so I took a different original stock and will refinish it I'm about 90 percent done. I'm thinking of shortening the fore end/handguard a bit but I want to keep a sort of original look and it wouldn't make me unhappy if the guys at the range looked really confused..
So if anyone has a Finn with the handguard rings that have screws that hold them together and the sling mounts on the side and bottom, I'd appreciate if you could measure the outside diameter and post it. I'm not going to ask you to disassemble anything but if you do happen to have one loose and could give me id it would be greatly appreciated!