Bandmaster 6G7-A Vibrato too strong

[Zouto]

Hi, on restoring a somehow battered Bandmaster 6G7-A I found out that the Vibrato is much too strong. I replaced caps, resistors, tubes for only little bettering, the throbbing is still too strong, while turning the Speed pot at max the vibrato effect totally disappears. The oscillator circuit also seems to take some time to start. Otherwise the amp sounds great.
Any help, hints much appreciated,
thanks
Zouto

[Zouto]

The broken Intensity pot is the culprit, so I've got to find a decent replacement 10meg RA pot.
Zouto