Looks very straightforward to me.
Blk-blk = 120 VAC DC measured resistance typically 2-5-10 ohms.
Yel-yel = 5VAC (measured resistance will be really low, less than 1 ohm)
Red-red = HV Red yel CT (measure roughly equal resistance between red-yel and either red wire) red-red resistance can be ~~100 ohm-250 ohm
The remaining browns are your 6.3 VAC, should also measure very low, less than 1 ohm
The 5 VAC and 6.3 windings will almost seem like shorts.
We also take a clue from the LENGTHS of the wires. We expect the 5 VAC wires to be just about the same length. Same with the 6.3 volt, same with the HV but not necessarily the HV CT.
One of the safest way to tell if you are unsure is to find an AC wall-wart (HAS TO BE AC and MOST ARE NOT!) and power up the alleged primary with the AC out of the wall wart. Let's say the wall wart is 15 VAC. Then each secondary should put out 15/120 their normal volts. Thus a 5 volt winding should put out 15/120 * 5 = .625 volts. The 6.3 winding should put out a little closer to .8 volts.
The HV winding can still give you a shock under these conditions, 15/120 * 325-0-325 = 15/120 * 325 = about 41 volts across half or 82 volts across the whole (red to red) winding. I ALWAYS make these tests from one leg of the HV to the center tap so I am measuring half the HV. You want to have alligator clips on your meter tests leads. You also want to be a little careful connecting up the primary side, don't get finger-lazy because "it's only 15 volts" because when the power goes off, the collapsing field can generate what might be a surprisingly highish spike.