the issue with this was that class has many methods, and we need only fields (props), no methods.
Did Google search, StackOverflow... no simple solution...
Then I "asked" ChatGPT, and sure enough it provided a useful answer, it works in this case!
type ITable1Fields = Omit<InstanceType<typeof DbTable1>, keyof DbTable1>;
in typescript how to get interface with fields from a class without methods