[chimera]

Aren't income taxes a relatively recent (note, relatively) twist on generation of revenue for the federal government? The original Constitution could not have required public disclosure by candidates since there was no income tax back then.

It took Amendment 16 in 1913 to start it. I checked Amendment XVI and it says that the government has the power to levy taxes, but it says nothing about Presidential candidates, or anyone else for that matter, being required to make them public.

[Sasparilla]

...Aren’t income taxes a relatively recent...

Yes, however there were other taxes at the time of the writing of the Constitution.
Remember “Taxation without representation?”

But,taxes or their payment were not tied to the qualifications to run for the Presidency.

The taxes referred to in
Article I, Section 8, Clause 1
aren’t tied to the Presidency at all.

The Congress shall have Power to lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States