Serial No. doesn't match Mercury configurations Scheme

Mercury Tag, Mercury V6 black max 150hp 2.0 liter, non fuel injection.
Data tag says ser no. is A139064

Having difficulties upload image of tag.

Those are the only numbers on the tag I found. Other places to find information?
Installed on 1987 Ranger 373V which I am looking at purchasing.
Please help.

In 1986 Merc introduced an entirely new line of many of their models.

In preparation they started building them in the latter half of 1985.

Up until that point (1985) all the serials (production numbers) were all digits (1234567). For the "new" models they switched to an "alpha-numeric" serial.

So the A13xxxx (which actually has a "zero" in front of it in the actual number) equates to a "1986 model" that was built in late 1985. Those actually produced in 1986 as 1986 models had starting serials of 0A9xxxxx, but they are mechanically identical.

This parts listing should be applicable to your model even though the serial looks "funky": http://www.marineengine.com/parts/mercury-outboard-parts/v150/0a904646-thru-0c100860-usa