This could take 6 months or perhaps a year.  After that, i suggest part time.  Even a variable schedule so there's no pattern of presence and absence.

You realize that large organizations like BGE have multiple checking-up kinds of personnel.  In addition to the central auditing dept, BGE has extensive checking up going on throughout the departments.  There was a Cash Mgmt section of Finance doing its own check-ups,  internal checking in the Payroll Unit and the Accounts Payable unit.  Cashiers adjacent to appliance sales locations have individual and supervisor balancing of cash drawers. The warehouses have auditors, both on-site, & central.   In addition there's internal security employees, including at warehouses.  Also clerical personnel in transportation and shops depts. do balancing & control.  And there's veery intensive controls and checking at the Calvert Cliffs nuclear generating station.  I took helicopter rides there, while doing an audit there.  Yes OP is quite different, very much smaller, less elaborate than a large organization.

A single position for OP internal auditor should be OK.  And there should also be some review with OP supervisors to make sure they are on board with things they can do regarding exercising and maintaining internal controls.  I'm not sure whether Mendelsohn did any of such kinds of briefings. 

Virtually all OC hotels have a night auditor, some even two or more.  Balancing everything overnight, 365 days/yr. 

Tom