Thank you AVB for your comments. New blade purchased and installed, but had to be genuine Husqvarna blade, which was $45-50, as I couldn't find an after-market match for genuine part number 531 00 50-45. Still has a little sideways vibration, but as mentioned, the motor is rubber mounted, so I guess that could be normal.
Starts first time, after I replaced the flywheel key (sheer-pin) again.
Thank you to all Forum Members who have contributed to this post and I hope it may help others with similar issues.
Have a great weekend.
Regards
Daryl
[Linked Image]
[Linked Image]

Environmentally friendly recycling at it's best