Bigotry was
a sticking point; you're perfectly correct that there were many subsequent hurdles to cross had we not run into that one. It may not have worked out, and I agree that such changes are difficult.
In this case, however, it was reasonably blatant:
I spoke to the two leading (and, I believe, only) exclusively history teachers at the local public (middle and high) school. This was in a very small community: less than 10k population. One of them was an acquaintance of mine, and had indicated that they were having problems with student engagement. They were initially receptive given my previous work with them. To be clear, I wasn't coming at them with "here's a new entire curriculum I wrote; replace yours" or "you're doing it wrong", but rather an idea that we'd have a few weekend sit-down sessions together and come up with a way to structure some world history units around Ibn Battuta's writing as a jumping off point (not as the primary text, but as a means of creating engagement--think "you've read some of the textbook history of Somalia and the passages about it from 'The Travels'; explain how Ibn Battuta's observations reflect the economic, religious, and environmental realities discussed in $big_dry_textbook").
However, when I explained that this was a work by a Muslim scholar and that his religion was a frequent presence in his work, two things happened: my acquaintance immediately asked if it would be worth the time to "cut" around any references to Islam in writing by/about Ibn Battuta that we might use (taking for granted that it would be excised, just questioning the difficulty). Then, his colleague said, and I believe this is verbatim, "I'd rather not bring in [to the classroom] material from that faith." We gave up more or less immediately after that. Perhaps I should have negotiated differently or tried harder.
I also spoke to the principal/lead teacher of a very small/remedial private school in my area, and he candidly indicated that his close relationship with some of his students' parents concerned him regarding the frequency of references to Islam throughout the source material. Unlike the other two, he actually took the time to read it, and gave a candid answer, which I appreciated.
Edit: missed details.