Um, a #30 is bigger than a 1/8" bit, so I think you're perfectly safe. A #20 bit is ideal for a 5/32" rivet. If you stuff a 1/8" rivet in a 1/8" hole it just makes life hard and is not best practice.
Disclaimer: I can't count the number of times I've read on this forum that a #21 bit is better than a #20 for a 5/32" Olympic rivet. The manufacturer and most rivet vendors advises a #20 and that's good enough for me but to each their own.
Summary, you're good to go
1960 Sovereign 33' Pacific Railroad Custom