3D printers range from cheap to extremely expensive. Decent small one can be bought for less than $800 in a kit form, all parts, ready to be assembled or even fully assembled. I won't be endorsing any of the specific shops as there are quite a few. Complete kits can even be bought off fleabay, even cheaper.

The tricky part is sourcing ABS filament at decent prices.

For the interested, Kickstarter does have lots of printers for small form factors at very affordable prices. Though one has to wait for a long time. Anyways, great to see a project like this hear, good luck!

Yes, they will easily be able to handle such small smooth undercuts in a smooth shape like an impression.

I will slightly retune GR07's driver, since I know how to improve on the original tuning - which is quite good already.

Project continues. I hear the required impression materials are soon to arrive, meaning week or two.
In the meantime, I'll have some Sugru to experiment this weekend. We're running a bit of experiment and some Instructables.
Mine will be about shallow/medium fit impressions and perhaps a universal but customized ear tip as well.
3D scanner project will be resurrected using a dynamic grid or interference scanning too, also this weekend and later.

Measurement microphone is also near, should get out of customs office momentarily.
Calibrated Dayton Audio EMM-6, real cheap and supposedly better than "staple" Behringer ECM8000, see Parts Express.
I do have proper recording hardware with phantom power.
However, what I don't have is a real coupler, so I'll improvise using a silicone tubing of correct volume. Later perhaps my own ear canal negative mold.
One of the molds will probably be an ear and cheek simulator - but that later. For now, IEMs.
Pics of the setup will be coming.

Mold making materials - acrylic, silicone, silicone tenderizer, mold release etc. have been ordered as well, should arrive next week.

Also received GR07 Flagship edition.
Better tip selection thanks to foamhybrids, but none of these are still suitable for deep insertion. Best results with Hifiman long biflanges with "gap" between the flanges or with Hifiman small biflanges. Both ar a tiny bit too large, need to be pushed past the stopper and are just clutch fit on the IEM.

Annoying to audible 6.3k ringing (depending on depth) and some boost giving an edge to the sound, bit subbass drop, reduced air, but it seems they did something there to the shell, sound is less bassy and more airy than I remember. It's a minor but good change. It also is silver and looks and feels thicker. I'll let it live for some time in normal form.
So it's likely the patented nozzles are the source of their ringing or the thick metal meshes in them.

Kinda a real difference after all the Hifimans and especially minor modded Sony MH1 which are nearly linear and excellent fidelity. (and possible to improve yet more I think.)
5 years... they sound outdated nowadays. I'll try to make them shine, the issues are related to both shell and fit much more than the driver.

Pics will be incoming on weekend assuming Sugru® experiment will pan out. And even if it won't.
A friend apparently has some molding silicone left from another project too, so I might be able to create the measurement negative.