Did this in my own foor with some spare amtico a while back & have just added the tram line ! Took some doing as I don't have a guilly but very happy with the result !
Its a long explanation mate Shame I didn't take pics of how did it ! I'll try explain in a bit when I get home ! In the meantime have a think or if anyone else wants to have a go ???
I did something similar in collage copying a picture in a magazine. 25 years ago though in vinyl tiles but bigger. But I used dividers to make points on the floor so all sides were the same. Then after cutting a few rhombus shapes I used them as templates and cut them on the gilly. Hard to explain without showing you.
God knows ? Now I've done it & when I get a gilly its pretty straight forward & not much material so prop cheaper than a pre made motif or similar ? As I said God know ? What do you reckon ?