As you know, you will never get your money out of your project. Very few American guns could justify the trouble and expensive, let alone a Spanish "off the shelf" gun.
You would be better served to look for an ICD 28ga. You can find these guns NIB at between $6,000-7,000 (4E) and have a game gun that you can use and watch the value go in one direction...that's up, by the way. I have 5 of these guns (2 in 28ga.),use them all and they are all worth substantially more than what I paid for them.
If these are not for you, there are plenty of Parker Repros out there that, from a cost/benefit basis, have the same characteristics.
