Hi Kevin,
I'm glad that you understand about the ownership of personal arms. The only way that you could legally (and morally?) claim the use of those arms was if you had a fully documented paternal pedigree that listed all the siblings of each generation back to the original armiger. That is what the College of Arms would require for them to allow you to use those arms in your own right - and, believe me, the research fees of the College of Arms are not cheap, but there again, 'yer gets wotcher pays for' and you will find that the College will do a very thorough search if you pay them to act on your behalf. Even if you did all the research yourself, the College would have to verify your research before taking any action.
The entries for Arundel/Arundell in British Armory number 11 - there are none registered in the name of Arndell. If you peruse the Visitations of Cornwall (which, unfortunately, I do not have) you should find, along with the Visitation pedigree, the blazon for the Arms of the person you mention. Once again, having got that pedigree from the Visitation(s), you then have to do the authenticated link to yourself, working backwards from yourself in the male line. As I mentioned, you will also have to do a search for siblings of each generation to ascertain just to which blood-line you are linked. Only the eldest son of each generation may have undifferenced arms - each of his brothers would have to have those arms differenced by some form of cadency marking, such as a crescent for a second son, or a rose for a seventh son, etc.
As mentioned earlier, only the College of Arms, as the original issuing authority, would be able to verify if you were able to lay claim to those arms, either undifferenced as a direct bloodline through the eldest sons of each previous generation on your paternal side, or if you were able to bear those arms with the appropriate cadency marking if your bloodline was through a cadet branch of the blood-line.
Sorry I couldn't have been of more assistance in your quest.
Regards,