Like with all the dents and scrapes? Because a scan is the best tool in that case.

If it's just a motorcycle helmet, you'd likely have an easier time finding a model that's close enough and using that.

But yes, you can 3D scan and print a miniature of it. Maybe post in a local sub to see if anyone can meet you somewhere. Or else you'll have to ship it. I don't have a scanner unfortunately or else I'd love to help.

I'm glad your friend survived and I wish him a quick recovery!

You can create a full color 3d model of the helmet including signatures by using photogrammetry. A phone is enough to do it, there are even apps that do it for free. There are also desktop apps that are open source that can do it. Color 3d printing is also possible with technologies like HP (Multi) Jet fusion. Hobbyist are unlikely to have them but a maker space might.

I used to work for a company that would have been your best chance to get this done, but the business didn't survive the pandemic.

3D scanning is perfectly plausible; hell it's not that difficult to rig up an old Kinect (from an Xbox) to do it. Bespoke 3D scanners can get expensive but you can probably find someone to do it. Some 3D scanners will only catch the shape of an object, some can do color as well. The tool I would want to use for this is a structured light scanner, like an Artec Eva.

Most 3D printers would be up to the task of making a little helmet shaped object, but not get the color, especially the signatures. Common FDM or SLA machines aren't up to that task. The only tech I know of that'll get you a full color 3D print with the signatures and such will be a color SLS machine.

Selective Laser Sintering is a process where a thin layer of fine plastic powder is laid down, and then a laser shoots the plastic to melt some of the grains together to form a solid object. If you hear about 3D printed metal, this is how that process is done, just hotter. Some SLS machines can also either spray ink or drop colored powder in order to form a more or less full color model. These machines aren't user friendly, so you're really only going to find them in professional settings. We didn't even have one, so when we used one we contracted with a service that had them.

Back when I was working for this company, I would have done the 3D scan and the prep work to turn the raw model into a printable model in-house, and then sent the file out to the fab shop. I'd expect this to run at least a thousand dollars maybe more. And I don't know who I'd send you to these days, especially not in Canada.

It's definitely possible. Depending on the budget, you can take the helmet to a professional that does 3D fabrication.

I'd say the first step should be to find a local maker space and see if anyone there can help you. Most will have 3d printers, and some might have 3d scanners. If they don't, maybe someone there personally owns one.

Amusingly, this was just a bit down in my feed

No.

(this is the motivation he needs)

Everyone else is correct that you can scan the helmet and 3d print it but it won't include the signatures which you seen to want as well.