Is "Whistling Death" a dealer of some sort of engine? I notice you are a "Trading Plus" member. If so - Why not do as I was advised - place your interest in your signature line - It saves any confusion when posting about a product and it also generates plenty of enquiries (Well it does for me) - some of those become sales.

Anyway - to Answer your question/s -
The 45cc has the same pattern on the exhaust as the Peak 45cc engine.
The 50cc has the same pattern as DA50 & DL50
The 26cc has the same pattern as SPE
Thje 100cc has the same as the DA100 & DL100
The 65cc has the same as the Peak 65cc
The 150cc has the same as the DA 150

I am not sure about the 20cc. It is new to the range and I don't have any first hand experience with it (yet). My main market doesn't tend to use much of that size of Gas engine But I do have a couple on order and will evaluate them for market suitability once they arrive. I don't currently have a plane in stock that is suitable for it and am trying to decide what to use for the evaluation plane - maybe one of the other dealers can help out on the information for that one.

I am not familiar with Just Engines products - so I can't say for sure if their product will fit. There are so many different manufacturers out there that nobody can genuinely "know all" about all products - even though there are some here who may appear to do so.

One thing that I do know for sure - is that the RCGF dealer network is a group of people with strong technical backgrounds that readily share information with each other - we try our best to have the best information available for our customers but it does take time for us to collectively know everything