Can you clear up one other thing please whats the story with the side holes? Why are these such a point of interest? Does it just help determine the age?
If you mean the side skirt mounting bolt holes and the associated casting bosses, yes the presence of these on the
left hand side [from operator's POV] of the chassis, along with the RHS 'edger channel', is definitive for a Model 4 chassis.
Absence of these holes/bosses, on a chassis that has the edger channel, makes it an early 'Model 5 Special'; a Series 1 if it has the Predicta lugs on the axle mounts, Series 2 if the lugs are absent.
These 'Series' designations are just what ODK members have come up with, to define the major chassis feature variations which occurred during the production run of the Model 5, BTW.
They're not 'official' designations, but still very useful in working out where a given mower fits into the production sequence.
