hose or pressure washer nozzles?? valve seats?? what are they??

My partner handed me these 3 little things this afternoon, with the general comment "I found these in the truck I'm cleaning out...I don't know what they are or where they came from...do 'ya want 'em"...?? And anybody that knows me even in general (not to mention in here) can probably predict what my answer to *that* question was...??? <LOLOL>

My first guess would be either of the two in my title here -- little interchangeable nozzle parts for something to shoot water (or pesticide, or??) out of. The '3 sizes of valve seats' (old fashioned faucet parts, or maybe engine parts?) was my next guess. Their remaining bits of old corrosion (they've not been cleaned in even the slightest way for these pics) suggests they were something that used to be in proximity to water, at least.

Shown here with a US quarter and common ballpoint pen, each are the same diameter but differ in their exact 'height' and 'orifice size'. They also appear to be made of brass, the smallest of them might actually still retain a little evidence that it (or them all) could have been plated with something silverish colored at one time.

Anybody gotta *real* clue for me?? ;-) :-) :-)