Originally Posted by
ATOBTTR
You can use "ITA Matrix" to search by Fare Class (see instructions on how to book specific fare-codes) and then "Book with Matrix" which will then generate a link to DL.com to book the specific itinerary generated by ITA Matrix.
ITA Matrix:
https://matrix.itasoftware.com/search
Book with Matrix:
https://bookwithmatrix.com/
Unfortunately, the link to DL website generally results in DL just repricing to lowest fare class available. Only Priceline link seems to preserve booking class specified in ITA search.