Jupiter to Scale with Kit Hill Memorial?

[Knight of Clear Skies]

I put together this composite image showing the Kit Hill Memorial and Jupiter to scale for a short article on the Caradon Observatory website.

Trouble is, I'm not entirely sure I've got the scale correct. The same camera was used in both cases, an old Philips webcam, but for the Jupiter shot I used an ED120 & barlow back in May 2016. I think it was a 4x barlow and have scaled the image appropriately (AstroMaster 114 focal length is 1000mm and the ED120 is 900mm, or 3,600mm with the barlow). Unless I'm misremembering and it was a 2x barlow, or if I scaled rather than cropped the original image before uploading to Flickr.

Is there anyone who could give me a sanity check on this please? I also need to work on the text of the article to avoid misleading anyone. I was careful not to inadvertently recommend the AstroMaster 114, the scope itself is decent enough but the mount and finder are dreadful.

[Knight of Clear Skies]

Did a bit of math on this to check the angular sizes and I'm more confident that I've got the image scale right now.