Since you are the artist you are free to do anything you want!
However, as a professional framer I have several recommendations to you as to properly handle this work.
First, I'd like to commend you for caring enough to both inform your client of the nature of the substrate and also for caring enough to want to properly handle the work for its best preservation.
You certainly can handle this piece like a watercolor... rice paper hinging or using corner pockets to hold the art in place with matting and a backing board. Glass is fine on an oil painting and actually is a better preservation treatment than having a painting freely exposed to the elements. Glazing provides physical protection and also helps to alleviate rapid temperature and humidity changes. Museums use either glass or acrylic glazing for this very reason.
Being on a paper this oil should be under glass and matted and if it was mine that is exactly the treatment I'd use or, as Steve suggested above, it could be hinged to a rag board and float mounted in a frame with spacers and/or matting to keep it off the glass.
For oils on canvas I still prefer to have it properly varnished and framed without glazing simply because you can experience the tactile qualities much easier than when glazed.