Re: Dunnett R-4L 2011/12 Model Vs 2013 Model???
I don't think there is any way to tell the new version from the old one. Maybe by the package, or, when they got their supply in. You'll have to take their word on it.
Personally, I'd just go with a new P-85 or P-86, with a new butt that is the same as what you have. The new die cast butt from Ludwig doesn't match the hole spacing.
On a '66, I'd keep it as "stock" as possible. If you go with an 85, spray it with a teflon/silicone type lubricant, that way it will work very smoothly and not bind. It's pretty cheap, made by DuPont... ($4.95 at Lowes, etc...)
The P-85 and P-86 have the same hole spacing as what you have.