Welcome to Photrio.
Looks like a 9x12, and the 135mm Tessar lens was only used for this format. Some Quarter plate cameras were made but the format looks quite different.
Just replied to your PM on the LFPF, now I see the possible fit I may have some holders. Will check over the weekend and let you know. For film you'll also need adapter sheaths, Eastman Kodak made them in the US, I've sold all my spares
Post some pictures of the edges of the GG focus screen holder and the film pack.
Ian