I'm in the EXACT same situation Don Z.
I found a free mobile style for download:
https://vborg.vbsupport.ru/showthread.php?t=263822
Other then some load issues I'm having with the style, I think it's the way to go. I would upgrade to vBulletin 4 but I have too many critical custom mods that I can't easily replace.
I thought Tapatalk would take care of mobile friendliness but nope!
Let me know if you find a different solution please.