Is the LEGO 509-1 set rare?

Yes, this set is from 1965 and is part of the Supplemental theme, making it a vintage collectible.

How many pieces are in the LEGO 38 Slimbricks set?

The set 509-1 contains exactly 38 pieces.

This particular set belongs to the Supplemental theme.

Name: LEGO 38 Slimbricks Assorted Sizes (509-1)
Brand: LEGO

Supplemental

Supplemental · 1965

Theme · SupplementalPieces · 38Set Number · 509-1Year · 1965

Used

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New / Sealed

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Is the LEGO 509-1 set rare?: Yes, this set is from 1965 and is part of the Supplemental theme, making it a vintage collectible.
How many pieces are in the LEGO 38 Slimbricks set?: The set 509-1 contains exactly 38 pieces.
What theme is the LEGO 509-1 set?: This particular set belongs to the Supplemental theme.