Duane,
I'd be wary of using measurements for bar replacement, as apparently there are several different ways to measure handlebars. If you really want an OEM replacement bar, I would try to find real ones on eBay or contact a place like
http://www.vintageiron.com that specializes in older bikes.
Here's the original bars - I did a quick relative measurement from the photo, and they seem to be about 6" rise:
Attachment:
1975 CR125M 2.jpg [ 78.82 KiB | Viewed 4931 times ]
These look similar - notice how tall they are compared to modern bars:
Attachment:
Vintage Handlebar Photo.jpg [ 12.28 KiB | Viewed 4931 times ]
http://www.ebay.com/itm/Vintage-MX-Hand ... 20bf3213a1My MR came from the factory with one of the 5 different bars specified for the '74-'75 CR125M. I replaced the bent/cut up originals with Pro Taper SE 'ATV Mid' bars, with 150mm / 5.9" rise (supposedly). These bars weren't even close - when I rode standing up, I was looking down at the front fender - but I liked the pullback so I used 2" risers, and everything's fine now. I measure rise with the bars upside down on a flat surface with the grip sections flat, from the surface to the highest point on the center section. Using this method, the Pro Taper bars were a little less than 4.5"; perhaps Pro Taper rotates the bars to get an absolute-max height reading or something.
Hopefully some of this was actually helpful to you.

If someone out there has found exact replacement CR125M bars or something really close, that would be great to know.
Ray