Recently published by Peter Lang, what appears to be a very light revision of the thesis which may be read at http://web.archive.org/web/20120229165521/http://www.scotthahn.com/download/attachment/2468
To quote the beginning of the publisher’s information (the rest of which may be seen at https://www.peterlang.com/abstract/9781454193654/2_title2.html?rskey=3uzSZS&result=2 “This book offers an innovative examination of the question: why did early Christians begin calling their ministerial leaders «priests» (using the terms hiereus/sacerdos)?”
On the basis of a speedy read my initial reaction is there is certainly something here and the proposal is certainly superior to that of Hanson which it seeks to replace, though I feel somehow that Stewart has not told the whole story. Nonetheless the observation of the possibility that priestly imagery has some connection with the maintenance of sacred space, which is Stewart’s fundamental argument, is perhaps part of the story which might be told.
With chapters on the Traditio apostolica and the Didascalia apostolorum it cannot fail to be interesting!
PS: I am not related, to my knowledge, to the author.
Edited in November 2019 to update links, both of which were broken.