I don't know whether this is the same publication that you have in mind, but when I was serving the Lutherans they had some very nice grey-coloured hard-bound books containing these Willan introits and graduals, published by Concordia. It may or may not still be in print. If not, you may be able to get them somewhere on the internet or from a Lutheran church which no longer uses them.

There is also Introits for Festival and General Use by Healey Willan (Leslie Music Supply,Oakville,Ontario,Canada,1950) which set Antiphons in 4-part harmony and psalms to introit tones.
There is also Introits by Henry G Ley,(O U P,1944) texts from various sources,including traditional introits.
And for good measure,does anyone know the beautiful 9-fold Kyrie by J M Asola in Francis Burgess ed A Polyphonic Requiem,(Plainchant Publications Committee,probly c 1920)It goes beautifully with Stanford in C and Stanford in F Communion Settings,which don't have nine-fold Kyries.although Henry Ley provided settings adapted from Responses to Commandments,published by Novello.

Sad to say, CMAA had to stop distributing the collection of Healey Willan introits we were offering. The Healey Willan Society, from which we had obtained the PDF file, found out that the work is still under copyright to the original publisher, so of course we respected that. On the other hand, it's good news that the publisher, Concordia, is offering to sell print copies, so the music is available.

I have the Willan book (form Concordia), however, what I can't find is the sheet that I made up with the correspondence of the Sundays of the Old Calendar to the New one; I know that the now-unavailable PDF had such a listing, and I am wondering if anyone has that available or can extract it from the PDF and send it to me.

I am not looking for the music, simply the redistribution (Fifth Sunday after Trinity = 11th Sunday of Ord. Time, etc.).

Better yet - here is the chart from the Willan book.