I would guess 6449 is a '95 or possibly '96, since mine is just under 4000 and is May '94. 11210 is much later, probably towards the end of the series. They should be dated inside the chassis, usually in gold pen written on the chassis floor somewhere.
The one with the brown cloth has been taken apart (or more importantly, put back together) by someone who didn't know how to do it right - the foam vibration damper strip is pushed out, which happens when you push the chassis back into its slot. The way to fix this is to take the chassis out, and put it back correctly - you need to remove the front grille first. There are six screws inside the cabinet. You can reach them with a fairly long-shaft screwdriver without needing to take the lower back panel off or even the tubes out, if you're careful. Undo them about an inch, not out altogether. Now, you should be able to pull the top edge of the grille frame out from the front, and remove it. (While it's off, you may want to gently hoover the speakers with a soft brush, if they're full of dust.) Now, undo the four large chassis screws on top. The chassis will drop about half an inch, and you can pull it back to look inside - disconnect the speaker cable and the two reverb cables first (remembering which way round they go) - and hold it steady with one hand under each transformer. You should be able to see the date. Push the chassis back so it's supported on the top edge of the speaker baffle.
Now, tuck the damper strip back up properly into its groove - there's self-adhesive tape on it and it should stick. Now get the chassis into the right position and drop the screws through into the holes, and lift it so it moves directly vertically against the damper strip instead of pushing it forward, then tighten the screws. Finally, put the grille back, drive the screws back in, and hook up the reverb and speaker cables. It's probably easier to do than it was to type this, when you've done it once!
The handle on the black one is probably about to come apart. Note: the top handle is not for lifting the amp, it's a steering aid when pushing it on its wheels
. The end handles are for actually lifting it
.