InMy40s
All cabs Chevy or GMC from 1960 thru 1963 and from series 10 thru series 70 were interchangable.
and that means everything associated with them,to wit,
windshields,doors,seats,in cab gas tanks.sheetmetal panels,etc.
The only one a little off was the series 50 trucks,or better known as a LCF or low cab foward.
In other words,a door from a C60 will bolt onto a C10 like you have.
A door off of a C50 LCF will work also but the foward edge,bottom corner,will be cut off on about a 45 degree angle to allow for fender clearance.
hope this helps.
regards,
steve sr.