That must have been a cool experience! The tracks sounds pretty nice, especially considering the little effort involved here.
But before you start investing a lot of time and energy into this project in hope of commercial success, remember there is ample competition in the field of piano sample libraries - especially of Steinway D concert grands, which are probably the most popular piano and thus most sampled.
Just to name a few bigger names of Steinway piano sample libraries: there is Galaxy II Vintage D (for Kontakt), Synthogy Ivory II German D and American D (with an own standalone player and VST plugin), Garritan Steinway, East West Quantum Leap Pianos etc. There are also plugins that use modelling instead of real samples but still imitate real pianos (i.e. PianoTeq D4 for a Steinway sound).
As Skaldir mentioned, the big challenge is not the sampling of the notes themselves, which is basically a diligent but routine piece of work except for the proper setting up of the mics. It is the implementation of all the string and cross resonance that builds up when using the sustain pedal. Different makers of piano libraries utilize different methods to achieve this, like separate resonance samples or a modelling approach combined with samples.
Just to give you an idea: The newest library from Synthogy Ivory II (the "American D", sampled from a famous 1951 New York Steinway concert grand) has all notes sampled at 20 velocity layers. The library takes up 49 GB of space, and that's only for the base samples, as the Ivory engine uses modelling to create the various resonances occuring in a piano. I believe it is common in these sampling sessions to use machines to trigger the keys, to get consistent velocities for all notes on all layers.
So, as far as I can assess your current situation, your product might sound pretty nice overall but would fall short in key areas like resonance implementation and velocity consistency and thus not be able to really compete with the big names.
Obviously, another piano library does not hurt and there will surely be some buyers, but your product would probably not stand out. For that you would need either unique features (like a new, better approach to resonance modelling) or sample a really exotic piano that is not featured by the big names.
So, while I definitely don't want to discourage you from doing it at all, I'd suggest you keep your expectations about the outcome reasonable.
