abergele, I too collect rare stamps, mainly victorian and have seen a good rise over the last 3/4 years.
However, I think the stamp fund is badly structured. It was a brilliant idea which is being marketed badly. Very few people will invest a minimum of £20K, even avid stamp collectors. The other thing is the charges left, right and centre.
This fund was correctly aimed at sipps but it is unlikely to happen...
Saying all that, SGI is cheap without the fund and is worth at least 120p, imo.
Good luck all.