Reassembling your machine during and after refurbishing various parts, is always more pleasurable when the old, corroded fasteners are renewed, preferably with the correct specification OE factory supplied parts.
More sizes of flanged bolts you may wish top consider:
Renew the fasteners and increase the pleasure of reassembly.
Add as many new parts to the same shopping cart as you wish, new washers and nuts for example, and still only pay the same single fixed price shipping cost.