An old friend now deceased once told me about a visit to AJ parkers in the 1950's as part of the RAF Rifle Team.
Whilst there one of the team saw an SMLE with target sights in SR"b" configuration with unusual figured furniture. It turned out to be Lignum Vitae
and at that time AK Parker's were experimenting with it on the basis that the heavy wood could be useful in target rifles.
The team were allowed to borrow the example for trials but it did not produce the goods in the way of reasonable scores and it was returned to parkers.
I've often wondered if it's still out there somewhere?