Vacuum Advance issue

The vacuum advance apparently became available in 1935 ('34s have manual spark advance). The vacuum advance diaphrams are all shot and the part is now obsolete. I have 3 diaphragm units and none of them will hold vacuum. So tried to improvise using a Pertonix adjustable vacuum advance unit.

• Original PN per IHC parts catalog "1857719 Vacuum control (less bracket)"...this is an obsolete Delco-Remy part https://www.delcoremy.com/find-a-part/product-details/1857719

• "IHC Part No. 43527H - Distributor vacuum control and support assembly (Delco-Remy 680-T)" from Instruction Book - Model C1. Could find nothing on this number.

• PN 1116088 (I believe)

Pertronix D9006 Flame-Thrower Adjustable Vacuum Advance Canister for HEI Distributor