Mystery bolts/screws

Sounds like a plan, the bolts are just plugs for the little oil reservoir in the end cap of the block so yep tape would be fine to keep crud out. When you get spare bolts, make sure they’re the same length as it’s just plastic in there.

Here’s an old post with some pics of the insides of a similar block to give a better idea of what you’re squirting the oil into.