ROBB, if it is sweep tube, run the other way.
A heath kit SB 200 uses a pair of 572B, it will also work with the Chinese manufactured 572B's with no issues.
You can find them for $300 to $400 or more depending on upgrades, new filter caps, soft start etc etc.
The SB 200 will work the WARC bands. It does need the tuned input reworked a little bit to make today's transceivers happy as this amp was designed back when there was real radios ( glow in the dark). Information is available on the net even for component values to rework the tuned input.
I have had both the FL2100B and the SB-200, The FL2100B has to have some mods done to make it stable, the cut off bias circuit as designed is not so good with today's high gain Chinese tubes, the SB-200 much better design.
The FL2100B does not monitor grid current, a design flaw IMO, the SB200 does monitor all functions.
It will give you 500 to 700+ watts out depending on the bands with about 85 watts of drive. This is using 220vac but it will work on 110vac with a slight decrease in output. Can not beat those old heathkits if they are used correctly and not abused.