Hi Friends,
I started to try to amplyfy my Baritone Aeola way back in the 1940's , and went thro all the various set-ups that you have mentioned . but as I was playing quite often with dance bands against line-ups of saxes, trumpets , piano or Keyboard , bass & drums, nothing I did was really satisfactory until I found some crystal Mikes that were recommended to me by the very experienced Accordionist, Jack Emblow.
The mikes were of French manufacture and I purchased 4 of them from Henry's Radio on Edgware road , London in 1972. They cost me 60 pence each and , mounted inside the instrument between the grill and the action about halfway along each side ; they have been very reliable & satisfactory in all the various situations that I have encountered. The mikes are connected in parallel and the leads brought to a Female 1/4" jack on the outside . I use a standard Guitar type lead to connect to the amplyfier.I have used many types of amplyfier over the years, and my current one is made by Watkins of London and is identical to one supplied to Art Van Damme for use with his accordion . A couple of years ago I purchased a Guitar Wireless unit , and this allows me to play without a lead connected between my instrument and the amplyfier. This is of course much safer and reduces the possibility of feedback.
Because the Mikes are facing inwards, very little sound from other instruments is picked up. I hope that the foregoing is of some assistance to you , but please ask if you require further information.
Good Luck, JOHN NIXON.