I'd be a little skeptic about it. Most importantly, there's probably a reason, why you have six APs instead of one. Routerboards are very nice devices, but they are not magic. Outside in open space and with proper antenna, 600m might be ok. In buildings, no way.
Then about the RB itself, it still might be good enough for light tasks, but it's old and weak. Also there's huge difference between RB133 (three ethernet ports) and RB133c (one ethernet port). The latter has only L3 licence and it does not allow to make AP for more than one client. While it can be upgraded, it's not worth it. Plus this old RB is likely to have only b/g wireless card.
In any case, you can use it for testing. To reset it and create a simple AP is just few minutes of work. If you have antenna, you can test the signal levels. But for actual use (assuming one AP would be enough), I'd swap the board for a new one with integrated n radio.
Excessive quoting is useless and annoying. If you use it, please consider if you could do without it.