This was in the mid eighties, so my memory may have faded. However the engines were definitely throttled back (to what extent I don't know). We definitely commenced a slow descent to maintain speed, and we definitely put out a Mayday (we were at no more than 10,000ft). You are probably right, the flt deck were following SOPs, they behaved as usual in a highly professional manner. Most of us had experienced an R2OH or 2 in the past, so realised that the problem would likely go away once the levers were shut so no real drama. We did of course dump fuel & RTB. I dare say the incident report is still out there buried in a file somewhere...