Chicago Blues box combo guitar amplifier Loose tube sockets preamp noise recommended upgrade

A very well built amp except for the tube sockets. The owner told me the octal tubes / sockets were looser than a goose. He was also experiencing strange rushing noises. So he decided to stop playing it until the problem could be resolved. Inspection revealed the weak link. I ended up changing all to Belton Micalex. Lucky the new sockets lined up with the chassis holes. Otherwise drilling would be a bear. The chassis is stainless steel. I was able to perform all of the work with the chassis still installed in the cabinet. Two of the 12AX7's were tricky since they were at the rear. Using tweezers and patience resolved that issue. I added a 1Ohm resistors to each output tube (pin8) for easy bias adjustment. The amp is working well now and back in the owners hands.