1st off, without a letter you can't get an exact date. You've got an welded kick stand and two numbers look right but the last three don't. Based on kick stand and numbers on Bottom bracket you're gonna be 47-52 and with that you should have s-2 rims too, not drop center ., I could be wrong but it also looks like somebody ground off your serial numbers and added in the last 3 regardless, you aint got a letter. The white paint under the color on bottom bracket means it's also been repainted, it would be redlead primer, not white. . Maybe the letter is under the paint?