Wilsons Sandbox

Hi all I have begun the unpleasant task of replacing both the rear body mounting brackets on TC 4282 as they suffer from metal fatigue and substandard repairs. Having removed the rivets I presumed that the plates that sandwich the mounting brackets to the chassis would slide off the spring shackles with a little bit of force applied. However, they seem to require a lot of force! Before I get nasty and cut them off has anyone had experience of removing these rivet plates? Are they pinned to the shackle or are they just an interference fit requiring a modicum of heat to expand them to get them off? Thanks in advance for the considered responses and sage advice. Yours faithfully Ian Debenham TC 4282 [Non-text portions of this message have been removed]