I presume you are referring to the rubber spiders which were fitted to what the factory called
'Series 1' Aurelias ( up to and including 4th srs B20, Aurelia saloons and B24 Spiders) as opposed to the fitting used on S5 & S6 and B24S Aurelias?
If so, the aluminium holders can over time wear sufficiently that even new rubber spiders will be a little loose when everything is bolted up. In this case I have successfully once used 'V' shaped steel shims to take up the wear although tbh I much prefer to use less worn aluminium parts these days.
And if you propshaft is currently vibration free just mark the positions of everything before disassembly .
Hope this helps.
Chris