Estes Tiger Shark, anyone have a calibrated fin template, or can I do it off plans?

Estes Tiger Shark is a two stage with glide recovery of the booster (Centuri Black Widow similar)
Looked up both of these, I can find plans for them

estes tiger shark here, scroll waaaaay down: https://www.scribd.com/document/106518028/Tiger-Shark-Rocket-Plans#

century black widow here https://plans.rocketshoppe.com/centuri/cenKB-6/cenKB-6.pdf

but I can't find a CALIBRATED template

The plans for the tiger shark include figure 3 with a diagram of the booster with some measurements. Is it reasonable to assume the diagram is to scale, and I can extrapolate the chord length of that diagram, and use it to calibrate the fin template?

Go for it. What I do to collect dimensions is to use Paint and draw lines where I need a measurement and one matching a given dimension. Get the ratio of the pixel lengths and use that as a scaling factor to get your other dimensions. Plus, it looks like they included fin templates as well.