I've read conflicting things on the interior stain. The original owners manual mentions a combination of teak interior surfaces and 'cherry', and from what I can see of the Howard restor-a finish cherry colour online, this looks like it might be a fair match. But in the Tartan 37 'a history and celebration' published book, they mention the interiors are 'Mozambique veneer'....?
Many years ago I played around with some stain-colours on a piece of marineply to try to match. The stain was an Australian brand (
https://www.feastwatson.com.au/products ... /prooftint), so probably not available across the pond. But I found, rather than directly mixing, an undercoat/s of 'golden teak' followed by a top wash of 'maple' (it's important not to simply mix the stains) worked really well to bring out a depth of colour that matched the cabin-- the yellow in the undercoat glowed through the top wash of red. I experimented with different numbers of coats of each layer to find the best match, but can't recall now how many coats of each worked best... Maybe two 'golden cedar' with one 'maple'?