Today I found the you can use the glue from a small hot glue gun to make LRF replacements.

In fact I was trying to re-attach the two remaining LRF’s (two are lost) but they would not stick to the glue - when I realised the glue by itself was a suitable replacement :).

On the other hand, if you are trying to justify the purchase of a new notebook - as my sister has rationalized the purchase of a new car - you can just ignore this little tip.