Hi there, I recently had some really helpful info from a number of members about my full size bass accordion so I'm hoping you can help a little more... I've thought long and hard and have now put this accordion up for sale on ebay...I'd rather it was played than stay sitting in it's box forever....however there are still some parts I'm not sure about - I know it's pre-war so doesn't have many sound changer buttons/levers - it could have one though that I've found out about through trawling the internet it - and there is, above the buttons, a long bar which can be pushed (as can be seen in the attached photograph) ...is this the sound changer?...I can't play it properly (it does still work) as too heavy and large for me so not accurately being able to test. I'd appreciate any help...I'm feeling more and moe like a absolute novice!!!