Does anybody know where I can get info on a 1942-42 5x7 Tech II? I got one in a trade & neither Bob nor Linhof can provide me any info. Specifically, I need to know if the back is temovable (& how) & what filmholdes it takes. The owner told me it takes single-sided filmholders, but I can't find any info on them. Thanks for any help & advice.