Dave,
Found the following parts available at Redneck trailer supply. The 2 5/8" on center shackles are about the same thickness as the shackles removed from your Ollie. Sorry to hear about the clearance issues. Redneck trailer has a toll free number on their site, too.
4 each: 2 5/8in Galv Shackle Strap 115052GALV
http://shop.redneck-trailer.com/p-830-2-58in-galv-shackle-strap-115052galv.aspx
1 wet bolt/locknut pack: Four 9/16 x 3 Shackle Bolts w/Nuts and Grease Zerks SP04-021
http://shop.redneck-trailer.com/p-1526-redline-916-x-3-shackle-bolts-wnuts-and-zerks-sp04-021.aspx
Hope this helps,