I think OP misunderstands the existing distinction normally made between...
customised - 'stock' item modified/personalised to suit the customer.
custom-made - 'one-off' item designed and produced for the customer.
Note that although custom-made can apply to anything that can be "designed" and "produced", it's often replaced by custom-built in the case of products with a primarily "mechanical" purpose (cycles, cars, yachts, beds, chairs, etc.).
Also, simple custom is often used with less "physical" things (diet, menu, toolbar, etc.)
I suspect that OP may have been misled by marketing men (and boastful owners), who blur the above distinction by referring to their merely customised stock products as custom-made because that's already the "stronger" form, and they hope to gain "kudos by association".