oh ok i was going by the fluting on the lens base. i know the later gen 2 did not have it
also being were i am i have scene and worked on some franken versions
There are many crossovers and exceptions; more between gen 1 and 2 but also gen 3. Gen 1 had smooth fake metal shiney bands around the bottom. Gen 2 had vertical ribbed texture on the base, some a lot more than others (to the point where some seemed smooth). Gen 3 the dome just had a raised area at the bottom. Gen 1 domes could have their height altered easily and the first respond-a-strobe had quite a bit of height added.
Also gen 1 and 2 domes came with cutouts for the respond-a-strobe first an "almost round"
par 80h type insert then edge alley light insert. Gen 3 did not allow for a cutout, clear domes were required to make a directional strobe a different color than the dome. The domes in 1, 2, and 3 all came split and with filters. The gen 2 rotator filters are almost impossible to find now (people think the most recent ones fit, but they don't). The tone/warmth of the colors, usually amber, varied a great deal. There was deep amber, pale yellow, and ones in-between. Blue, green, and red varied a bit, but not as much. Some domes had stickers/labels on top, gen 1 and gen 2 usually had embossed logos on top. The embossed labels could be contradicted by the stickers. Gen 3 had stickers on the base only.
Gen 1 and gen 2 domes can be interchanged, their base plates were metal, gen 3 were plastic and larger. Once you get into gen 3 you start to get rotators that don't fit in gen 1 and 2, but the 4x3 strobe and Austin 360 strobes do. Interestingly, the original
par 36 strobe from the first respond-a-strobe was so tall it caused them to add dome height to gen 1 but it is even oversized for gen 3.
The variations were almost endless and could be caused by field replacements, home brews, and even factory "specials". Really no combination is off limits if the components fit. Whelen also offered retrofit rotator replacements for gen 2 well into the second phase of gen 3.
I have a PDF on my home PC that lays out the progression, there is a bunch of crossover. Also Austin Electronics having their own versions led to a more fluid timeline.
tldr; If you can physically combine it in a responder bar, it was combined.