My attempt to photograph two ID plates. The Smithsonian no longer allows
monopods for photography, and the engine is behind guard rails, so none of the
text is discernible, even in the full-resolution version of this photo.
I did not notice this at the time, but toward the left (behind the circular
fitting ringed with bolts) can be seen the white stencilled digits "204"
followed by a digit that looks like it could be a '6' (it definitely does not
look like a '9'). Rocketdyne used a different serial
number scheme for its F-1 engines than did NASA, although only the first
digit of the serial numbers differed; in this case, a Rocketdyne serial number
of "2046" would correspond to a NASA serial number of "F-6046". Of course,
this is engine F-6049, so the mismatch is somewhat curious but is not the first
instance where the serial number on the
throat is different from the serial number on the thrust chamber (in the
linked instances, the thrust chamber in the foreground at right has "2010" on
its throat but the engine at left has "F-2010" on the lower portion of its
In all cases, it is the NASA serial number which would appear on an engine's
"master" ID plate.