pattern - Two missing numbers

Two numbers go at the $?$s, what are they and why?

$733,\space \space 716,\space \space 645,\space \space 565,\space \space 324,\space \space 276,\space \space 77,\space \space 75,\space \space 64,\space \space 56,\space \space ?,\space \space ?$

Hints

As noted in the comments these are the final two numbers in the sequence.

The sequence is strictly decreasing and contains only positive integers
(that narrows them down to $1485$ choices).

We could extend the sequence to the left using the same logic, but there are many ways to do so.

Answer

The sequence is:

733, 716, 645, 565, 324, 276, 77, 75, 64, 56, 7, 4

Because:

The sequence consists of digits 1-7 and each digit x occurs x times. There is one 1, two 2s, three 3s, three 4s, five 5s, six 6s, six 7s. The next two numbers should have a 7 and a 4 in them to complete the pattern. Since the sequence is strictly decreasing, the last two numbers are 7,4.