NEWBIE Needs Help with Old Sundance Weir Assembly

[Schergz]

Hi. I 'm new to the forum here and am hoping someone familiar with older Sundance tubs can help me out. I was given a 1990 Sundance Serenna which I have up and running. This is my first hot tub so I don't know much about them. My Question is from most of the pics I've seen of other Sundance tubs they have a removable lid directly over where the filter sits. This model doesn't. Here's some pics.
My question is if you look at the second picture you can see a "flapper" like this and that's all that came with the tub. On this style tub, should it also have this and are they meant to work together?

Thanks

[Kev B]

 The middle picture is a generic weir gate that I do not believe Sundance ever used. The bottom picture is the good old classic Sundance system. They do not work together

[SerjicalStrike]

The "flapper" picture you posted is the only one your spa needs.  The other weir will not work with your spa.

[Schergz]

Okay. Thanks for the reply.