105 trailing arm changes

[gbeston@domain.elided (George Beston)]

In the case of 105 spiders, the change in front bushing size occured
sometime after the introduction of the 1750 Spider veloce.  Early 1750
Spiders have some similarities to the 1600 Spider (aka Duetto) not shared
by later cars.  These include side marker lights located behind the front
wheel wells, fuse boxes under the hood on the rhs inner fender, and the
cannister air filter on the exhaust side of the engine.  Those spiders
still had the smaller bushing at the front of the trailing arm.  All of
these details changed within the same series number (105.57 for lhd "Euro"
versions).  My best guess is that for spiders, this change took place early
in 1968.

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