In stage 3, attack the left, right, and middle turrets on the battleship and they should start blinking red. Destroy them in the order they're blinking for the 1up.
Destroy the vakula (those flat, spinning gray things from Xevious, I guess?) before the last boss in stage 5 for a 1up.
I was aware of the spinning wall at the end of Stage 5 having a 1UP inside, but wasn't sure about the conditions for unlocking the Type C, and stage 3's hidden 1UP is news to me.
With this info, one could get the three score-based extends and the two 1UPs to have up to 7 lives (and if you left autobomb at its default setting, 21 hits) prior to reaching the TLB.