lend leased planes : where and when ?

I've checked : the VVS were never delivered a single B17 via lend lease, but mustered a small b17 fleet from salvaged emergency landed planes.

same goes with B24, but they purchased one under very unusual conditions, which was latter recorded as lend leased.

USSR asked many times to be delivered heavybombers but it was always refused (most of the time because the US needed all the planes they built).

It shows how hard, long, and demanding it was to build a heavy bombers fleet, which was discussed here about a what if German heavy bombers fleet.

And sorry about the P39 but while checking details, I found some contradictions in my usual sources, and now I've got to sort things out.

It's merely about the different engines which equipped various variants of P39. Any info welcomed.