Now that the Hitachi / Quasar thing is sorted out......
Yes most the time a chassis is used for many models & sizes
with little or no differences in the MAIN chassis. Much
like cars. My 03 Mercury Grand marque is almost identical
to my 04 crown vic. My neighbors 02 Lincoln Town Car
is almost the same also. Most the major parts are interchangable.
A TV maker would build a "new" chassis every 2 or 3 yrs.
An example is Zenith. They came out with a new chassis
@1974 19EC45 for 19" sets. Same chassis used in 17",
23" & 25". All almost identical. They came in different levels.
19" came with & without remote, in consolettes & pedestal sets.
Also a tilted back set with wood grain or white & woodgrain
cabinets. All have the same major guts with different tuners etc.
This is why we speak of chassis numbers so much here. For
us that spent a life fixing TV's to keep the wolfs from the door
its what we can relate to.
73 Zeno