I was also surprised to receive #27 today; I was about ready to write off IAPR as another dead item. I was disappointed that there was no "focus aircraft", but the list of articles to appear in #28 indicates two "focus aircraft" (the Foxbat and the Huey - part 1) as if to make up for that.
As for an index, this was on the last page of #27:
"All current subscribers......will receive a free copy of Cumulative Index: Vols. 1-28 when their copy of Volume 28 is mailed out. For non-subscribers, the cost of the index is $4.95, inclusive of delivery within the USA."
I continue to be disappointed with the lack of content on aircraft of the past. When the complementary "Wings of Fame" was discontinued, it was implied that IAPR would be about 50% modern and 50% historic, but it has never been even remotely close to that. Issue #27 has about 110 issues modern and 45 pages historic, which is actually better than the average has been, but IMO still not balanced enough.