You have something special. You won't need the Vandys any longer. I have two pairs of Type A's, one similar to yours & one pair of AIII's.
I'll have to recheck my serial numbers on mine...I think they are in the 1200's. Right around this time the AI's became the AII's. I think the AII's just had some wiring changes with the same parts as the AI's. With serial numbers in the 1400's I'd say you have AII's.
RE: the woofer surrounds...my AIII's need the same thing. I'm told (by Mark@Snell) the replacement surrounds should be a "light" material. I will have Tri-State Loudspeaker do the work on them. Dante at TriState suggested including as much of what's left of the surrounds in the packing to them so they can look at it & match it as closely as possible. Once you have new foams you'll need to break them in so they loosen up. Snell used to do replacement foams, but last I heard they stopped(they subbed it out anyway).
Value $$: It depends on how bad someone wants them. There was a pair of AIII's (9/10 condition, new surrounds) on ebay two weeks ago that went on a BIN sale for $2000. This might(?) be on the high side, but I can't say the buyer made a foolish deal. One way to look at it is that they are quite long in the tooth from an age standpoint. A more realistic way to look at it is how they sound relative to what's available today & at what price. AIII's with the right signal fed to them can be stunning.
Power: You should have enough, but the Type As are not afraid of power(4 ohm, 86dB, ~35-18500Hz). I run around 300-350 watts/ch into 4 ohms on my AII's. My amp is SS, pre-amp,CDP, DAC are tubed. I biwire only. I have the external crossover, but haven't used it, yet.
Once you're ready to light them up, let me know & I can give you some hints on setup. Make sure you have the correct top on each bottom...it matters.
Great score, you'll love them. I'd like to hear them with all tube power.