About 1960 Shimabuku Tasuo trained in Kobudo with Taira Shinken. From that training two Isshinryu Kobudo traditions arose, Urashie No Bo and Shi Shi No Kon No Dai. Taira while the most knowledgeable Kobudo instructor sharing his knowledge was known to suggest using a systems core kata to learn a weapon (separately this may have been the genesis of Kusanku Sai) and to create new kata for study. There is no record of how he shared with Shimabuku.
For the kata Urashie No Bo there is no equivalent kata I can find on the internet. A Japanese student of Taira, Inoue Morokatsu preserved Urasae No Kon in his 3rd volume Ryukyu Kobudo. The photographs are hard to interpret but it appears to be much the same kata. As its photographs are printed in the Japanese manner Top to Bottom, left to right I am sharing some of the Urasae No Kon applications with this piece.
Shimabuku Tatsuo’s version of the form Urashie No Bo today.
For the kata Shi Shi No Kon No Dai there is nothing similar to it in the Inoue text, Joe Swift suggests Soeishi No Kon Ni in the Taira tradition may have some of the same moves. Here is the Ryukyu Kobudo Shinokai version of this form
Another form to consider may be Sakugawa no kno sho
Where I see a similarity, as you can see both these forms are considerably shorter than that of Isshinryu.
There is no question that Taira added much depth to Shimabuku’s art.