Considering all the angles of carbs and exhausts of other engines making a fit into pattern models difficult, the SAP was tailor made for narrow pattern fuses. Fat fuses are bonus

I think I described how the choke is worked before. One of the photos shows a nyrod with a piece of nitrile tubing on it, cut to correct length. The hole in the chin cowl is a sort of keyhole.....pull the nyrod to the end of the rubber tube, and engage the plastic nyrod into the key.

The frontal shot clearly shows a snug fitting chin cowl that will aid engine cooling. Would you believe that Webra heads actually grazed the chin cowl, hence the relief hole shown. They are much larger than the SAP head