[Heathkit] SB-310 & SB-313 documentation

[Gerry Steffens]

As a restorer/collector/radio historian, I collect and restore both radios
and documentation.  I have a couple of each of these radios and multiple
manuals for each.

I am wondering if there was any standard approach to dating/part numbers
etc.

I have 3 potentially differing SB-310 complete manuals.  The dates and part
numbers are shown below.

Part #                    Date
595-896-02          no date
595-896                7-14-67
595-896                7-05-68

I also have the SB-310 modification kit installed in one radio with
Instructions (SBA-310-3, dated 10-10-69 and manual part number 595-1048).
This kit installation changed the highest frequency band from the CB band to
the 15 meter band.

Were there two earlier Modification Kits, suffixes 1 & 2?  If so what were
they?

I  have 2 SB-313 complete manuals.  There are no dates but different part
numbers.

595-1330-04
595-1330-05


If almost appears that Heath may first have altered dates for different
printings and then switched to no dates and adding and incrementing part
number suffixes.

Does anyone know the significance of these differences?

The dates are obvious, but is the "no date" before or after the two dated
310 manuals?

Are the part number and suffix differences merely printing designations or
are there actual changes to the radio or manual changes/corrections?

Are the date differences merely printing designations?  Or have the manuals
been updated.?

TIA for any assistance.