The TricoClassics will not work as they mount to the arm completely differently.

I am missing the metal sleeve that goes on either side of the refill to give the rubber rigidity. If I have to order a 15" refill anyway, I am assuming that the metal sleeves come with the refill.

Pictures of my blades and arms for reference.

how much of that side shim stuff do you need ? i have a bunch of that stuff in my "wiper parts" drawers. hundreds of years ago, i attended an auction and ended up with a lifetime supply of blades and refills, and used up a bunch of it already, but still have three drawers full of stuff ranging from 6-24". many times, i have taken the refills apart and used the rubber without needing the shims [side reinforcements]. let me know how much of that stuff you need, and i'll send it to you, gratis, provided you can wait a few days.

OK. I think the crux of the problem was that it was too narrow of a refill. The trick will be to find a new refill of the correct width.
Use a caliper, machinist or drafting rule to check these dimensions-

Correct Refill Dimensions:
Width of refill reinforcing rib (usually metal) is 0.380"
Length of refill reinforcing rib is 15 1/16"
Length of refill rubber wiper 14 13/16"
Raised section in middle (distance between wiper's claws) 4 9/16"
Ht from windshield contact edge to rib .42"

A somewhat close replacement seems to be Trico 43-150
Width of refill reinforcing rib .34" with two sections in middle at .4
Width of spring retaining clip on tip, approx .38 -.4 (free)
Length of steel rib: 15 1/8"
Length of rubber: about 15"
No raised section, retension by clip on tip.
Ht from windshield to rib: .41"

There may be better fitting refills but that's what I've come up with so far. Maybe Moparx will have something for you.

Classic Industries has new refills for 16" Anco push buttons. If someone has the correct 15" rib, it *might* be possible to cut the new 16" rubber to fit into the 15" rib.

The problem with buying correct old stock is that the rubber may be dried out and brittle. You don't know until you get it. I did it to get the measurements and it happened to be in decent condition.

Cross referencing:

Analysing the parts books..
In 1967 all A-bodies got 15" Anco push button wipers; But in 1968 A-bodies could have ANCO with two claws (bridges) or Trico with single bridge. The Anco refills for 1967 and '68 are the same.

The B-bodies in 1968 came with more possibilities - the 2 door cars could have either the Trico or Anco 15", same as used for the '68 A-bodies. Whereas the 4 doors and wagons could have a yet different wiper (maybe a 16"?)

Anco had several names for the push button wipers including 'red dot'.
I've seen posted (I think in the FABO thead) that some factory Anco push buttons were black and rectangular. They work the same.
Trico called their version of the system Latch Pin, hence LP series refills seem to be for the Anco push button blades.

edit: The Anco 19 series linked in the first post is too narrow. The U-15 is much closer to correct width, but would need to try one to know if that cross section will actually fit.
Below is from Anco's 2014 catalog: