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

@glm911 First off, congrats on 46 years of musical enjoyment from your system. That's pretty amazing in itself.

You've gotten some very good advice here.  "New stuff" sounds great, and bang-for-the buck (or is that sound-for-the-buck?) pegs the needle on the cost/performance meter.

It's impossible to throw objectivity, subjectivity and emotional attachment in a blender and try to predict what's going to make you happy in the future.  I'll just throw this out there (if you head isn't spinning enough already):

IF you love the Altecs, you can make them sound better than original. While I have extensive experience in speaker upgrades, @pdreher has hands on experience and owns a pair.  Not knowing the internals of the Model 19s, I can only speak iin generic terms.  That being said, the crossovers of that era used production quality parts, cabling, connections, etc.  Those components (caps in particular) are ready for replacement.  IF the Model 19s are like many speakers the crossove boards can be pulled and shipped off for upgrades.  IF the budget allows, custom, hand-built crossovers can be built and shipped to you, complete with pigtails ready to put back in place.  As a "speaker mod'r" the goal is not to paint a mustache on the Mona Lisa, and try to make the Altecs not sound like the Altecs.  The goal is to deliver the performance the original designer would have produced if technology, time and budget were available at the time.  They will still sound like Model 19s.  Just much more transparent, focused, detailed, and musical.  Not quite a polite British loudspeaker, but something smoother that you can play louder, longer with less fatigue.  

As for the Pioneers, they are still very desirable (and valuable) pieces.  You can get a reliable "fix" if you want to make the journey to the hifi repair shop.  Or, like the Altecs, they can sound better than original.  (A Spec 1 left our shop sounding much better than it did when it came in). 

As some suggested, adding a phono stage would be signifcant sonic upgrade and take up very little shelf space.

@OP - What model is your Music Hall Turntable. If it's one of the more budget offerings, you should include a Turntable / Arm / Cardridge upgrade.

As regards amplification, a high quality integrated is more than sufficient for your speakers given their efficiency. Passlabs has been mentioned and is excellent.

I'm not sure of Copland from Denmark is distributed in the US but they make excellent integrated amps.

Prima Luna has also been mentioned and is a good choice in Tube amplification.

If you are using old cables with your system currently, be sure to put aside part of your budget for decent cables. The list is endless, but in terms of widely available cables, Audioquest do a very good job.

@charles1dad

I acquired the Franks about a month ago and the Music Reference RM9 MKII has been sold to a good home. The Franks have proven to be a better match for the Altec’s, as they allow me to hear deeper into the music.

@curtdr wrote:

"If you're intent on keeping the Altecs, OK... but speakers too have come a long way for the money.  If you like lively and yet with that "audiophile classy sound" and old-school looks: Klipsch Forte IV.  aprox $5000"

My Model 19's superseded Harbeth 40.2 Anniversaries and Dynaudio Confidence C4's and I can say without reservation that I get more enjoyment from my 45 year old refurbished Altec's than the well regarded Harbeth's and Dynaudio's... so one should not assume that newer speakers are better or more enjoyable that classic vintage speakers.  If the OP is satisfied with his vintage speakers, I would not replace them with something newer without validating  first hand that newer is automatically better.

@pdreher I agree for the most part and myself I own and love Epi 100 speakers and their little brothers Epi 50, with some updated parts from Human Speakers.

So, as I don’t know the Altecs in question, I don’t necessarily assume that new speakers are "better" than those... though I’ll note that even you have refurbished Altecs.

However, that said, speakers, like amps, have come a long way in "bang for the buck" since the 70’s, especially when you factor inflation, and there are some relatively inexpensive, $2000-5000 range, choices that perform at an astounding level that only the very, very best from "back in the day" could aspire to. Think about the updates over time to the JBL 100, the KLH 5, and the Klipsch Heritage... There are also far more choices in even less expensive "budget" speakers these days that only a select few from the 70s could come close and that only if updated.