Your Mikimoto Pearls sound Gorgeous! Yes, great idea to get them re-strung! Did you purchase the Pearls yourself from an authorised Mikimoto retailer? I suggest you take the item to your nearest authorized Mikimoto retail store and ask them to send your jewellery to Mikimoto to be repaired.
Regardless of where you bought your Mikimoto jewellery, you can always contact any Mikimoto boutique or any authorised Mikimoto retailer for assistance.
I think MAHARAJA is your nearest Mikimoto store: MAHARAJA 105 W. 23rd St. Panama City, FL 32405 (850) 763-4224
Mikimoto recommend that if you are sending products to them (other than in person) that you use a courier service or recorded delivery to confirm that the products were received by them.
The Insurance depends on the value of the Pearls and this cannot be determined without seeing the pearls first. For instance, the Pearl's SIZE- which is determined by measuring the Diameter of the Pearl, plays a huge role in their value.
This beautiful Mikimoto Black Pearl Lariat Necklace (below) of 11mm Black South Sea Culture Pearls with pavè diamond rondelles with pavè diamond clasp in 18k white gold retails for $60,000.00
Please let us know, how you get on Nikki, and if you are happy with the assistance you get from the authorized Mikimoto Retail Store.