Leaking terrazzo shower base drain seal

Hi, I have a 3' x 5' terrazzo shower base that was installed by a plumber in 2003, all new construction. It has a 2" PVC straight pipe within a brass drain flange which was sealed with lead.

Recently I noticed some water damage to drywall below the drain area. I inspected around the drain and noticed that the PVC drainpipe has visibly cracked loose from its lead seal and risen quite a bit towards the drain cover (house settlement?).

What is the best/surest way to re-seal this lead-PVC connection?

Thanks in advance.

I don't see how pvc could be sealed with lead...maybe a picture of what you have would help. Well, maybe a cold packed joint, but I'm not so sure they work particularly well.