The lever filling series (numbered 5x, or fifty-something, with the final digit determined by the nib size) is most commonly represented by the model 52, with a #2 nib.
Anyhoo. Perhaps the two most common trim forms of the Red, the Woodgrain and the Ripple (excluding the #7 which is- perhaps- found only with cap-band) pens are those with goldfill caplip band and goldfill clip/lever, which- in 52 size- would be catalog model 01852 (the 018 indicating the cap-lip band and with the goldfill trim going along with that), and the 52 proper, with a bandless cap-lip featuring a thin notch in the Rubber near the cap-lipa.
Later in the 1920's Waterman intro'd the model #7. The number 7 was derived from the model 55 (a bigger version of the 52 featuring a #5 nib). It packed a goldfill caplip band and goldfill trim. The top of the cap had an inset color band which reflected the same color name marked on the nib. The colors indicated different nib tip styles.
Shown below is the only #7 of its sort i've ever seen. I had doubts at first about it, but the more i conisder it the more it seems quite original and real- though i am open to counter views.
The pen appears to be a #7 but with Bandless cap-lip. Besides that i've seen no ads showing "bandless" 7's and that I have never seen such a pen before, the pen shown now does not even have classic "Bandless" styling. Look at the pic and see if you can tell what is odd (beyond even it being a #7 and Bandless)

The anomalies with this pen is that are that a) it has no cap-lip band (odd enough for a #7) and that
In the pic below see a large waterman 58 with similar trim to the usual #7 (goldfill caplip band, lever, clip) which technically is 01858 (pen is marked just 58 of course) and a tiny 51 V Bandless with the notch we describe, near the cap-lip.

I wondered about this Bandless #7. Could it represent a funky repair? Was the cap shortened to deal with damage in the area of the cap-band??? Could it represent an under-the-hood addition of a cap lip?
But, no. At least i believe, "no". ;-)
The pen cap is normal length. There is no evidence of any filling of a bandless notch (say, if someone frankenpenned a Bandless 55-cap to make a cap for a #7, not that filling HR is easy as filling plastic). The pattern matched perfectly. Bright light inside the cap shows no tampering.
I don't know. Still. A very nifty pen. In our final pic below, see the Bandless #7 next to a typical banded #7

Thanks for peeking.
david