Production runs of 10,000 was quite typical of Fisher, but the document inconsistencies with this preamp series between version runs are significant -- both with the Service Manual, and the Owner's Manual. The unit on the left in the previous pic says it is for a model 400CX, but clearly shows a picture of a CX-2, and covers a serial number range that could only be for the CX-2, so the shoes and shoe laces don't match, which has always been the problem with information on these preamps. There also was definitely a version that looks like a true CX (the one on the right), but has CX-2 circuitry installed, and CX-2 stamped on the chassis. Maybe it was covered in the Service Manual for the serial range that's in between the serial range shown for the two manuals shown in the pic (i.e.: 20001 to 29999).
Such problems were hardly uncommon with Fisher, with numerous other models having Service Manual examples where the pic of the unit on the manual cover does not match the serial number range of the unit actually covered in the manual. With this line of preamps, it seems that the primary issue Fisher was having is that it couldn't quite keep the model number straight between the versions when it flipped from the model CX, to the model CX-2, with there being both Service Manuals and Owner's Manuals having text or data pertaining to one model, yet indicating by model number that they covered the other model. With Service Manuals, the serial number range is really the most dependable indicator of the information provided within a given manual, while model numbers and pics may or may not always match up appropriately.
Dave