Rather upmarket from the a model presumably there was also an early b model but i ve never seen or heard of one.
Serial number yashica mat.
Next is mtl 4110xxx and two with mtl 5080xxx numbers.
Taking lens is yashikor 80mm f3 5.
Bay 1 mount for filter hood tele and wide lens adapters.
Typical taking lens serial numbers from to 66 series pigeonflex 215xxx 255xxx 18 244xxx 269xxx yashima flex 37xxx 44xxx 6 272xxx 285xxx yashica flex b 4xxxx.
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.
Film tlr 6 6 medium format 120 12 frames or 220 film 24 frames built in light meter.
This model was made from approx 1970 1986.
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.
You can refer to the table below to check about the date of your yashica tlr source of table.
The next example is mtl 4012xxx with lens numbers both 368xxx which look like typical late 1962 numbers.
The sources i could find said it was made until 1971.
Very few mentions of the production range online and the existence of the massively popular later 124g model makes finding information about the plain old mat version difficult.
Camera mtl 4021xxx has 285xxx lens numbers which look like they are from 1961.
Based on that site i believe the serial number of my yashica mat dates it as having been produced in january of 1971.