That's crazy. The handles are a part which can be ordered on their own for a start. They cost about £18. The thumbscrews are about the same price max.
Not suggesting it's the case here but do the toggles move freely now ?
I only ask as I buy a lot of motors and one thing to look out for is broken handles. Why ? As people often lock them together on the transom to prevent the motor simply being removed and lifted off. As a result they get snapped as ally breaks before a stainless steel padlock!!!
If the toggles are free moving it would suggest they may not have been snapped during "storage" - if they were it would be the actual rivet which would break not the lockable insert on the outer edges of the handle.
Sorry if that sounds a bit accusing, in my line of work you have to be.
Peter ~ Boatsandoutboards4sale ~ firstname.lastname@example.org
~ 07930 421007