Hi BB, both Jack and I came to the same conclusion, we need a good clear close-up pic of the fitted ID Plate to this machine and compare the serial numbers....

Here is a pic of the model range for 1974-1975, you will notice that the 3 SB Model 45's mentioned all have early model numbers....for the 14", 17", and the 20". Notice that the illustration is of a solid deck machine and that the Model 33 is still being produced and sold...In 1975, it was deleted from the product range.
[Linked Image]
The plot thickens...... grin
cheers

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