The next example is mtl 4012xxx with lens numbers both 368xxx which look like typical late 1962 numbers.
Serial number yashica mat.
The serial number on both body and lens are consistent with a manufacturing date of 1971 making this one of the first oldest of this model.
Camera mtl 4021xxx has 285xxx lens numbers which look like they are from 1961.
Yashica mat lm lens serial numbers are very consistent and these look like they are from 1960.
You can refer to the table below to check about the date of your yashica tlr source of table.
Rather upmarket from the a model presumably there was also an early b model but i ve never seen or heard of one.
Only one yashica a serial number 11611xxxx one yashica d serial number 12611xxxx one yashica 635 serial number 13611xxxx four yashica mats all serial numbers 14610xxxx two yashica mat lms serial numbers 15609xxxx and 15611xxxx and twenty three yashica 44lms serial numbers 16609xxxx to 16611xxxx examples have 9 digit serial numbers.
The yashikor lens was supposed to be an improvement on the yashimar but i suspect there s little difference both being rebadged tri lausars from tomioka.
Based on that site i believe the serial number of my yashica mat dates it as having been produced in january of 1971.
This model was made from approx 1970 1986.
Taking lens is yashikor 80mm f3 5.
Next is mtl 4110xxx and two with mtl 5080xxx numbers.
The sources i could find said it was made until 1971.
The serial number was the key though and it appears that serial numbers exist going up into 1973.
Bay 1 mount for filter hood tele and wide lens adapters.