Customs, VAT, and shipping precious items with complex value

TLDR: I am importing equipment to the EU which is super valuable but can’t be sold.

I am moving to the EU (France first) and need to ship my belongings. I own some industrial electronics which I use for work, which are extremely expensive (30k+ USD) at retail. I could never afford that, so over a few years I refurbished them myself from broken salvage units.

Since they are made from broken pieces, they do not have legitimate serial numbers and cannot be sold or shared with others. However, by all appearances they look like retail, and only a few functions are not working.

I can’t afford to pay the import taxes and VAT on the sticker price. I also want to insure the shipment, and the replacement value would be the full 30k+ since there is no other way to replace them.

What should I do? Can I insure the shipment and still avoid the customs? Can I write a document detailing the situation? Will they even have a way to contact me while I am still technically homeless in a new country?