I know of two collectors that have the I. R. mounted on US M1 rifles. I have seen one in person too. They use the same bracket holes as the M1C but a different mount. The really difficult part of this unit is finding the batteries and pouch from what I understand. On the Danishicon I. R. the bracket or mount is welded on to the receiver.

It was reported that US Special Forces were using the I.R. on the M1 Rifle in 1962 and it must have seen limited service in the early days of Viet Nam too.

There are also photos of the M14icon Rifle with the I.R.