Hi Jamie, Sorry it has taken so long to reply, but I'm just getting back into the swing of things after my hols in Brisvegas.
To your question, Your machine should be a 16" Model 33 manufactured at the earliest in 1960. The numbers on the brass data plate after the model number:(33) are the mower number which do not run necessarily sequencially, but could mean that your machine is Number 989 in the production run. You cannot, unfortunately, date any Scott Bonnar exactly by the data plate information.

Hoping this helps,
cheers2


Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin