The K model is a 2018.5, the same tank/bath layout as our 2018.5 RB. There is one set of black/gray in the wet bay compartment and the 2nd set of black/gray will be on the passenger side in the compartment to the left of the propane compartment, look on the right side up behind the filler panel and you should see them.
Brian & Jeannie
2018.5 Seneca 37RB with to many mods to list
2015 Jeep JKU Rubicon