Secondary air lid flaps interchange?

[mcx]

Can the later version secondary 1708 type  air lid doors interchange with the earlier 704/1705 versions…I have some heavily pitted early type and shiny new later type. Thanks.

[Cliff Ruggles]

The latest design airhorns used a larger pin for the secondary hanger bracket and the flaps were "notched" accordingly.  They still interchange with earlier units but you will have two small openings where they were notched for the larger pins......