By definition of how the 501st Legion validates approvability (as of 2012 and later), details must match within a single reference. That means that you can not combine references for details of parts of a costume. You must also utilize cohesive reference, meaning if one reference differs from another (in this case, book cover vs comics) you can not combine them and must think of them as separate existences for the purpose of approval. If you are basing it off the hilt from the book cover, then it would need to be the complete cover version submitted, which is not possible because there is not a full 360 degrees of cohesive reference even on that front.
We need some level of consistency to create any value of a basis of system for approvals, and picking and choosing which details we utilize from different references defeats the purpose of having an approval system at all, or being able to claim the highest level of quality in reference comparison that the Legion has. The only time this is not applicable in when there are differences within the SAME reference material, e.g. Aphra and her Barbie-like array of clothing and accessories options within a single issue of a comic. You are technically able to pick and choose different setups based on what she wears in the comics. Generally the same parts but in different combinations with some variation in designs (like her aviator cap and goggles that are different in every damn panel.
Now, that doesn't mean you can't utilize whatever hilt you want in your free time, but for the purposes of approval and trooping, the rules of approval dictate that you use and wear what is in the approval and the CRL.