There are some disparaging remarks here on the longevity and cheapness of the East German models. Whist your Wheatstone/Lachenal is likely to last without needing much repair for over a century, I have half a dozen of these cheap models and they all have kept good tune and are still in playable condition. You get what you pays for, but for learning on these cheap models are fine.

Yes individual reeds are easier to remove, replace and tune, the banked reeds are the same as in accordeons/melodeons and although you need to remove a whole bank to get at the internal reeds they are usually just held in place with a pin and wax and can easily be removed and replaced.