Be prepared for the same customer to submit the same check number more than once. . . It happens
Has anyone considered storing these check images in a database?
Whether you use vsam or a database, you need to write a bit of code that reads the uploaded images one-by-one and writes them to the vsam file or the database. I'd suggest that the "key" be part of the input record that also contains the image so that this new code simply reads the file and writes to the random data (vsam or db).