When I look in the 'Precept Manager' section some piano models show 7.4 and some 7.3 have all the models been updated?

The updates are listed as:
-    Refined physical model which benefits all pianos
-    New Steinway Model D recorded in New York Steinway Hall
-    New feature: Morphing
-    New feature: Layering.

The instrument version number in the preset manager is a priori independent from the Pianoteq version itself (although our latest trend was to have those two numbers more or less synchronized - sorry if that looks messy). In any case, the version number of the instrument, in the preset manager, is updated each time there is a change in the *underlying* model (not to be confused with the user parameters visible in the UI), which is for example the case in the NY Steinway D which has been revoiced. On the contrary, the Steinway B model was not modified in version 7.4, hence it kept the same version number as previously: 7.3, even if some presets are new (Felt I and II) or have been modified (for example Steinway B Recording 3 with the new Concert Hall reverb). I suggest to not pay too much attention to this version number, which is likely more useful to the devs than to the user.

The updates are listed as:
-    Refined physical model which benefits all pianos
-    New Steinway Model D recorded in New York Steinway Hall
-    New feature: Morphing
-    New feature: Layering.