Yes, This is one of the things that this guide was made and designed for, Ron
I have not tried it ,but I would be 99% sure that it would also work well with the ultra - saw Ron
Yes , Stors have them in stock. Ron
The Dremel SM840 Miter Guide can cut vinyl quarter round. For further assistance, please contact us at 1-800-4-DREMEL (1-800-437-3635), Monday-Friday, 8A-5P CST.