The least destructive way to check for a leak would be to insert one of those fish cameras into the register (like the ones used in cars to check cylinder condition).

Does anyone know if there is a special blank that has to be used for this cylinder?

Sounds like you are firing on all cylinders right now man!

This implies if the LL takes one month to place a tenant and a couple hundred dollars doing the always tenant turnover items (for example we always change lock cylinders, shampoo carpets, chemically treat the drains, deoderize/disinfect including use of ozoner). 

I use Schlage be365 deadbolts because they require physically turning them to throw the cylinder.

Search "Kwikset 99070-103 Powerbolt 2 Door Lock Single Cylinder Electronic Keyless". 

The magic is when all components are hitting on all cylinders (great location, operator, business type, parent company corporate support, etc.) 

I logged one stand in the NW Oregon area .. same area as AX man show logs in Vernonia OR.. and got over 450k net to me on that sale.. so it really depends on what you got.Even in CA.. you can still see 3 and 4 log loads going down the road.. big TREES  were as if your in plantation pine land there could be 75 stems per load.. in Oregon we averaged 20 to 30.. you want that tight cylinder 14 to 18 inch on the but and 10 to 12 inch tops no knots.. thats money.I have poked around at some timber ground in the east and you pretty much need to be looking at 200 acre plus type sales to have any real volume.. 

The cylinder isn' turning always.

Some will not even know what that cylinder is.