Lucky you. My Altec 19’s are long gone due to relocation/downsizing and I miss them to this day... I started using them with SS because it was all I had at the time but like a lot of other owners, transitioned to tubes after a while.
In hindsight there's a few low-power SS amplifiers I would have loved to try out with the Altecs: the Sugden A21, a Luxman or Accuphase class-A integrated, the Pass INT-30... or for much less money, a Clones Audio 25iR that recently left me speechless with its clarity and soundstaging abilities.
However if I had the 19's again I would definitely be looking for a EL84 integrated: something like a Leben CS300, an Audio Note Oto SE or a Triode Labs/Finale integrated. An Almarro A205A would also be an interesting, cheaper option.
And last but not least, thanks to their >99dB sensitivity you have the whole world of flea-powered SETs at your disposal... but that's a slippery slope indeed!