1903 missing rear sight

link from gun broker
https://images.app.goo.gl/zV47w5oqvuWUwgxGA

So, what do you think. Is it 2,663 serial numbers to "the good" (750,000 and above) non-brittle receivers, or play safe at 800,000 and retire it?

Thanks for the responses guys. I had no knowledge about the faulty receivers on these rifles, after reading up a little bit I am going to have my friend make the decision on if he wants to proceed or not.

My 1903 is Serial Number 1,000.XXX and was manufactured around February, 1918. I have reloaded since I bought the rifle in 1971, and I have never pushed pressures to or beyond "half-way" in the reloading tables. The "receivers" history is very interesting reading. I recall seeing a fellow at a San Antonio gun show back in 2009 walking the arena floor with a newly re-stocked, newly Parkerized 1903 he was trying to sell. I got close enough to see the serial number was in the mid-400,000 numbers. It was a nice "hang it over the fireplace rifle", in my opinion. I didn't hear his sales-pitch and therefor don't know how he was representing the rifle.