[Sca-cooks] Seville Orange Juice

[lilinah at earthlink.net]

There's a 16th c. recipe for Seville Orange Juice Sauce, in Marx
Rumpolt's Ein New Kochbuch, that calls for the fresh juice of
Sauerpomeranzen (Seville oranges), sugar, and cinnamon, uncooked. I'd
like to serve it with roast pork legs at the Boar Hunt Feast.
However, fresh Seville Oranges are hard to find any time of year. I
have seen them at a local market, but they are only briefly
available, and aren't around now.

Anyone have any idea what i can use instead?

I have thought of:
diluted strained orange marmalade (since it's made of Seville oranges)
fresh orange juice and fresh grapefruit juice mixed
fresh orange juice in which orange peels have been soaked

Thanks for any suggestions,
Anahita