I second Roger Hicks on the SV (alias Honeywell Pentax H3V). It's the most usable of the pre-Spotmatic cameras, because it features automatic aperture selection (vs. previous "preset" diaphragm), auto-reset exposure counter, 1/1000s top speed shutter with a single non-rotating speed dial (instead of separate rotating dial for slow speeds) and "modern" speeds markings (1/15, 1/30, 1/60 instead of 1/10 1/25 and 1/50 on older models). As stated by Roger, built quality is superb. I guess the cameras were still individually hand adjusted after assembly, just like Leicas.
The Spotmatic represents a significant drop in built quality, even though this camera has acquired some kind of a cult status, due to the fact it was one of the first cameras with TTL metering.
I don't regard the absence of a lightmeter on my SV as a big drawback, as a modern standalone lightmeter is much more accurate and sensitive than the CdS sensor of the Spotmatic. Anyway, I don't use this camera for rapid action shots. And for those that cannot live without an in-board meter, there is always the add-on speed coupled Pentax-Meter.
Check the great page about early Pentaxes on Frank Mechelhoff's website:
http://www.taunusreiter.de/Cameras/Pentax_main.html
Here are two excerpts about early Pentax "S" series built quality:
"Yet Pentax wasn't a million seller... the finish is superior to the later mass products, level to the quality of the best Nikon und Canon RF cameras of that vintage."
"my cameras... these are PENTAX before the mass production of the sixties, before the SPOTMATIC (1964), when Asahi Optical was a small, dynamic and innovative start-up firm at which cameras were build by hand in relatively small batches. You recognize that on finish... You even hardly recognize their age because they are so similar to the newer ones!"
Cheers,