Well, I'm back and as requested can update you.
Our outgoing flight from LHR was nearly 50 minutes late due, we were told, to ground equipment blocking the path of push-back. Surely when the plane was put on stand it was known what time it was due to depart and the airline/LHR should have made sure that all the trucks etc were out of the way?
Little time was made up on the flight, we had just over 2 hours to go through formalities, collect our bags, enter the arrivals hall and then turn the corner, up 2 escalators and check in for the budget airline flight from SIN to PEN. I can't fault JetStar at all, they were amazing with plenty of staff on hand, no queue to check the luggage in. Even the in-flight budget food I had pre-ordered was good! The flight pushed back exactly on time and arrived early in PEN.
On the way back, everyone was on board about 20 minutes before scheduled departure, we pushed back 15 minutes early and by scheduled departure time we were airborne!
We had 3 days in SIN before returning to LHR so managed to see the Jewel as well as T1..... it's a glorified shopping mall with an indoor water feature.
BTW the Bank and our lawyers in Penang had everything in order and it took just 2 visits of several hours each to conclude matters. RIP Dad, we had a safe and good trip even if it was sad at times thinking of you out there....