I have a IH Farmall H with narrow wheels - serial # FBH 65070

Also a IH Farmall W4 - serial #  SBH 28987W

I would like to find out what year they are. 

We have owned them for 40+ years and I've got them out of the shed, cleaned them up and they are running like a top.

Does anyone know what year they are by the serial number or suggest a website where to ask this question.

Thanks...... Whipper