I've noticed none of the A&A's locomotives came from the BA&A. So what happened to the BA&A's locomotives. If I was the A&A, I would have guessed that the BA&A's roster would have been the first place to go buy locomotives.
The BA&A had been long in neglect by the time they closed up. Every locomotive that they owned was old and tired when they acquired it. The roster consisted of power built from the 1870's to the 1890's. If they ran short on power, they borrowed or rented a B&S engine. After the B&S closed down the New York portion of the line, the BA&A was leased to a Pittsburgh Lawyer who tried to operate it. After a couple of years even they gave up.
The A&A battled with that previous lessor over 3 locomotives that were left on the property at the time of the foreclosure sale. The issue was over the value of the "scrap" locomotives. It must have been felt that they were in bad enough shape that it was better to seek newer power.
Even some of the A&A's early engines were tired when they were purchased. #2, 3, 4, 5 didn't last on the roster too long and there aren't many pictures of any of those particular locomotives.