You never can be sure about reproduction parts but the DMT description sure sounds correct.
If you read the complete link, it shows that it fits 73-76 A Body with the right part number for the 1975 firewall plate grommet 3748634.
Could this be it.
https://www.detroitmuscletechnologies.com/mopar-a-body-63-66-73-76-b-body-62-65-81-93-truck-lower-steering-column-tube-to-firewall-plate-grommet-seal-sc63/
2899327 pedal return spring 49 coils, painted green with orange stripe used on various car lines with V-8 engines in 67 and 68.
Go to My Mopar and look at code 14 - 06 -1 in the 67 and 68 parts catalog.
Reach under dash and unplug the plastic seat belt interlock module. It may be blue or green and measures about 4 x 3 inches. Should be easy to find.
https://www.moparmall.com/MoPar-PN-3501374-3746653-Seat-Belt-Interlock-p/jw-67196.htm
9080s Thermoquad was used on any 1977 Chrysler, Plymouth or Dodge passenger car with 440 engine, automatic transmission, hi - performance engine and non - Calif.
This info is from a 1981 Carter carburetor catalog.
A little more info on the Holley 1945 from 1974.
Two 1945 carbs were used on 225 engines in 1974 without Calif. emission pkg. and with auto transmission.
3751424 - Holley R-6724A and 3830402 - Holley R-6938A.
Chrysler superseded the 3751424 to the 3830402 in mid 1974 model year.
The 3870902 Holley carb was used on 75-77 dodge vans with 225 engine and automatic transmission.
3830402 is the correct carb for your 1974 duster with 225 engine.
Bendix catalog shows PDR0182 fits 10 x 2.50 rear drums.
Raybestos catalog shows 2947R fits 10 x 2.50 rear drums.
Both are available from multiple sources: Amazon, Summit, and many other vendors.
On Abodies the first electric grid rear glass option came on 1973 Duster and Dart Sport only. In 1974 it was an option on all Abodies.
See code 23-64-314 in 73 and 74 Chrysler parts catalog.