I am working on a T72B and would like to add the swing out armor skirts. According to the pictures I have there are four per side. Does anyone know if there is an after market kit for these or is this a scratch-built item?

Honestly, the only place I have seen the "gill" armour is on the T-64A from SKIF. Otherwise it looks like a scratchbuild. And I am not sure which models of the T-72 used the "gill" armor.

Sandbox,
According to Osprey`s New Vangard #6 T-72 MBT, the prototype ,Obiekt 172, used many external, and internal, features of the production T-64. Although a prototype the Obiekt 172 was put into prodution.Then, in order to correct any flaws, the Obiekt 172M went into production later designated T-72.These three all used the same "gill armour" as theT-64.
The T-72A on used the metal reinforced plastic fabric skirts.
Pete

My reference is from Concord publications and they list the T72B with 'gills' as standard production unit for the T72B. They also indicated that the gills were only installed for training maneuvers. Of course information on these tanks was limited and is open to interpretation. I thought it was also interesting that most of the photos appeared very staged. No individual or extra equipment tied down on the outside of the tanks.
Jacques, thanks for the tip on the SKIF T64 with 'gills'.

If you just want to build the holds for the flip out "gill" armour plates, go with Eduard´s PE set for the Skif T- 64. The pnels are included in this set.
If you need additional pictures of T- 72s mail me. I can tell you so far, that Czech T- 72s are equipped with them (so don´t use a final prodution T- 72A turret) and I think I have some pictures of Soviet ones equipped with them.

Violetrock