I made short Hammond organ solos in prog compilation (only modern bands)

featuring Standarte, The Flower Kings, Beardfish, Transatlantic and Jordan Rudess solo.

all mentioned are worth to check in the context of keyboard-driven prog

I think it was mainly just the prog metal bands imitating Dream Theater. An interesting thing is that the band Mastermind released their first two albums before Images and Words and yet their sound was similiar(in the sense that it was heavy and almost metallish at times and also prog)but was more influenced by ELP. They did have guitar but often the guitar synthesizer(I think it was)sounded like keyboards. An overlooked band these days worth looking into. Ars Nova were another ELP influenced band from the 90's but I'm not as familiar with them. Anyway, there was plenty of non DT clones and even non neo prog stuff from back then you just have to dig for it. 

Interesting band!  I used to listen it, and it's a weird example of ELP influenced band without keyboard at all :-) Guitar-synthesizer and MIDI pedals are responsible for creating all "synth-sounding" leads and textures on 1st two albums. long track "Brainstorm" is kind of a nod to Tarkus .

on later album Angels Of The Apocalypse they employed real keyboardist - no less than Jens Johansson

another obscure band is Symphonic Slam from Canada. their guitarist used a lot of guitar synthesizer, although there was also keyboard player   

...  ...  ... mannnnnn ... you know that's prehistoric stuff ... and most folks were not there to have a good idea! And listening to that old stuff ... where's the lyrics man?  ... 

LOL!!  I saw WR on April 10, 1977 with Al Dimeola opening (Land of the Midnight Sun tour).  Al put out enough guitar licks for two bands!! 

WR were sublime...Jaco, Zaiwanul etc.  Proof that you don't need guitar to be prog!  

I don't know what to think of the whole thing ... but I kinda have this idea that this is the result of the whole thing being relied on and dependent on 5 bands (so to speak), and in the end, what you find is that the bands that do not have the same "instruments" (or worse ... the sound) as the named top big bands in Progressive Music ... and it makes a lot of people forget/dump some of the things that were incredible that helped the music we love get here!

This is why I never forget the history of it ... and sometimes I think that we need more Admin support in this area ... and also one of the reasons why I did not like that "the instruments of pork" book ... it was an insult to so many bands and their creativity ... that in the end, made "Progressive Music" look more like a cartoon, than it did real music! There are/were many folks that had even further out and better instruments, that such a book will not report, because it's not this or that ... from the top five! Heck ... what the fudge will Jaco need an effect or a blue funky looking guitar for? Take that you "progressive" ... idiolist! 

Again, compared to all of Europe, many of the English bands were not exactly the best ... there were many bands bringing out a lot of great music ... that no one, even here, will even listen to ... however, today, there are more listens to different bands from various places, with only one concern ... the cookie copies are ... a bummer ... it's like their own culture and ability is not worth anything ... just to do a bunch of "metal songs" ... is actually weird for me!