I suspect you will get a better-informed answer if this thread gets moved to instruments.
Liszt owned several pianos. His favorites are said to have been his Steingraeber (a 200 cm instrument, 85 keys, relatively light action and great signing and ringing tone) and a Chickering (I have no details about size, but I would assume it was around 8'8"; I think one of these pianos is in the Liszt Ferenc museum in Budapest). Mephisto Waltz is said to have been composed on a Bechstein. There are paintings of Liszt playing Bosendorfer as well.
I am not sure, but I think the action of both the Steingraeber and the Chickering had "modern" double scapement, so they would have been quite responsive and able to play fast and loud without choking (which is generally not possible in a single scapement action like a Bluthner would have had and even worse in a ultra-light but feelble Vienese action like the Bosendorfer would have had). I am not sure about Bechstein, I don't know whether the Schwander action at the time had double escapement, but it would not surprise me.
The hammers would have been small compared to modern Abel blue hammers, which also makes the action feel lighter. The hammers would have been all cold-pressed and without lacquering, so imagine a warmer albeit somewhat mellower (and smaller) sound. (I mean, you can rip the roof off with an old Chickering, but with BIG sound, not the strident and clattery sound that you so sorely get from, say, a new NY Steinway D or a Baldwin SD-10).
Unless a historical instrument is properly restored and adjusted, playing a 150 year old piano will give you no indication of how this was supposed to sound or feel. Pianos are not like violins, you know? Soundboard crowns flatten, hammers harden, strings rust and actions break or simply become loose.
... and on the Earl King, chances are Schubert meant a tremmolo. Liszt's transcription, though, is to be taken literally (and in consequence played slower than the original song).