Hi Dusty R,
I know you are looking to repair your stock Ford front stabilizer bar. But if I were you, I would replace the bar completely with a heavy duty Helwig bar which does not utilize those suspension arm grommets. That gets around the problem in a different way. Yes some money and time is involved, but your 13 year old E350 chassis could probably benefit from a heavy duty stabilizer bar there.
If you look in back, you'll see you don't have any rear stabilizer bar there unless added afterwards by the RV manufacture or previous owner. If that is your case, I would order a heavy duty rear Helwig bar as well.
Both front and rear heavy duty Helwig stabilizer bars are friendly to install for the Do-It-Yourselfer. The results will benefit in ways that will surprise you. You won't regret the ~$400 investment and a Saturday afternoon.
If you are determined to fix what you have, call your local Ford dealer parts department and order a new grommet to grease up and hammer in the hole. If the other grommet has worn to an oval opening which is likely the case, buy two grommets and replace both. Any play of the bar inside the grommets renders the bar less effective.