Thanks OTEA -My source is SCAN (Scottish Air News) which states that Pan Am 707 N408PA arrived at Glasgow Abbotsinch on 3 August 1977 at 13.23 and departed back to Dublin at 14.43 operating Flight nos EI 1224 and EI 1225 for Aer Lingus. It was the first visit by a Pan Am aircraft to Abbotsinch as well. It does seem odd I have to say. There is a mention of flights to Abbotsinch in April 1978 by 707s belonging to Montana Austria (OE-INA and OE-IRA) for Aer Lingus but no more about N408PA and I have not been able to find out anymore about it which is why I thought I would try here.
Many Thanks anyway
Kemac