Sorry, don't have a design but I have seen at shows some nice folded and flame polished acrylic stands.
The nice thing about these(to me), done nicely, they are subtle and do not distract your attention from the engine.
Hi Chris, I may be wrong here, but I don't think you will find these are a commercial item as such. Possibly a cottage industry job or made individually.
You could try the MECOA site as members often display engines in a similar fashion.
Take a look at the Les Stone page on MEN too as he has a nice way of supporting his on a vertical brass rod and thick washer like base.
The engine looks good, time to get some fuel in eh
You can very easily make stands such as those by using a heat gun (or other heating device) on a strip of plastic whatever width and thickness you desire. Heat and then bend, hold in place until the curve is set. A sharp corner to use as a guide helps immensely.
One of our HMEM members has kindly made me a pair of perspex engine mounts on his CNC router free of charge. Now that's what I call service! I won't name the member lest he is inundated with requests. He can out himself if he is brave enough!
I have drilled and tapped the mounts to take 2.5mm SHCS.