nice find Dr Funk - just like the old school tail block - same same but different.
How is yr board building going? Got any new ones on the go? I am yet to attempt a tail block - maybe this is the time

Just did some reading on the new product - very interesting that they are interchangeable
David Barr has introduced “Shapeshifter”, an innovative surfboard removable tail system.There’s a wide range of surfboard tail shapes. It’s easy to get confused because, in some cases, the variations between them are subtle and marginal.The most important tail shapes are squash tail, square tail, thumb tail, rounded pin tail, pin tail, baby swallow tail, swallow tail, bat tail, and wing tail/tail.Depending on the ocean and wind conditions, you may pick one or another. David Barr, who has been surfing and shaping for four decades, is developing a new removable tail system that will shake the way we blend fins and surfboard shapes. Basically, we will be able to switch from a pin tail (big wave surf conditions) to a swallow tail (small summer waves). At the same time, we will manage these choices with a proper fin setup.The “Shapeshifter” comes with six different tail shapes: diamond, swallow, squash, round pin, asymmetrical right, and asymmetrical left.Is this the world’s most versatile surfboard?- See more at:
srfer.com/removable-tail-system-from-shapeshifter/