I feel it is time to upgrade my 1977 system.......

Go ahead and splurge on a Luxman SQ-N150 Tube Integrated Amplifier.  $3300 and plenty of power for your Model 19s.  Looks cool and takes up very little space!
Spend some time auditioning speaker cables, power cables, and perhaps a dedicated circuit and power conditioner (if needed).  I would look at Shunyata.  And don't forget room conditioning!
I don't know what your table/arm/cart is, but you will have plenty of $ left over to upgrade if desired.

Note:  I ran my gray box Altec VOTT A-7s with a Dynamo ST-70 (modified and upgraded with a modified PAS 3x) for years and loved it!  Nice juicy tube sound!  The Luxman is much more accurate and less "tubey", but if I had your speakers I would certainly audition it.

As @carlsbad2 said, your Altecs are ungodly efficient.  You're probably never pulling more 10 watts and mostly never more than 3 or 4.    Those speakers were designed in the days of tube amps and are quite happy with them.  I think your best bet for tube amps would be those from VTA.  You can either enjoy the immense satisfaction of building them yourself from well made kits, or you can buy them fully assembled and tested.  

As efficient as your Altecs are, the ST-70 at 35 wpc will still be overkill.  I'd run them in triode mode at 20 wpc and you'll still have more than you need.

https://tubes4hifi.com/

I’ve purchased a great sounding system for $10k. All purchased used. So yeah, it can easily be done. And it definitely helps to have purchased my speakers locally without worrying about shipping costs and damage. 

If the OP has a preference for solid state, perhaps a First Watt might fill the bill and be dynamic enough for the Altecs. Even a 30.8 seems like overkill here. An XA25 is very often described as highly transparent. I am partial to the Pass products, with some Class A power, and their service is exemplary. I would buy used and update if necessary.

I don't have experience with Sugden, but I'd be happy to give one a listen.