North Vietnamese Army Wounded Solider Identification Booklet with Photo 1971

This booklet documents wounds received in 1965 to an NVA soldier born in 1944. He apparently entered service in 1962 at the age of 17 or 18. The booklet has 1971 entries so this is when I suspect it was issued. I suspect by 1971 he had recovered and was sent back into the fight in some capacity as he was only 35% disabled and could serve some useful role in a support unit. A loose letter was folded inside and appears to belong with this booklet.