The commander-in-chief or the adjutant general may assign officers, warrant officers, and enlisted personnel on the retired list, with their consent, to temporary active service in recruiting, upon courts-martial, courts of inquiry and boards, to staff duty not involving service with troops, or in charge of a military reservation left temporarily without officers. Such personnel while so assigned shall receive the full pay and allowances of their grades at time of retirement, except that the commander-in-chief or the adjutant general may authorize pay and allowances in a higher grade when it is considered appropriate based on special skills or experience of the person being assigned to temporary active service.