I must go and have a look. What a lovely way to pay tribute to a very knowledgeable man. Thank you for posting this.
I should have said I believe the Maple Society sponsored the plant. The plant's map location to 1 square metre is in area TW200 approximately H8x S2x = SU3788x 2372x. SHHG has a major feature the Centennial Border (CB); TW200 (Ten Acres West) adjoins the CB centre circle to the west and the plant is quite close to the circle.
Acer pentaphyllum is a beautiful tree, especially in Autumn, but it's rather touchy afaik. I lost one, another doesn't have as beautiful colours as last year's : 2022 : 2023 : If I lose this one too, I'll definitely look for another one to replace it.