Just found my Grandfather in "U.S. Headstone Applications, 1925-1963". Was able to learn his Serial No., Enlistment and Discharge dates. More detailed service as 67th Co. 17th BN 153rd Depot Brig. C.A.C. 50th Hdq Co. 50th Artillery. It also states on back, enlisted in the R.I. National Guard - RWWS ?
This was a file added recently to Ancestry. Might want to check it out.