3-500Z instead of Philips YD-1130

[EFR]

Are there other SW tube freaks around?

One of these rigs that I looted, has an strong mold odour, but also an glass tube on its final, looks like 3-500ZG, but its just smaller, but still bigger than 3-400Z, old text has gone, only text on it is Phil..... Lets call him Phill (not Collins). So I think he is Philips YD-1130

Phil seems to be bit tired, only making 300W and grid current is negative, when idling alone at around 2.5kV on anode, anode current is 100mA, at around 2.2kV he idles at 80mA (two settings on PSU). On higher voltage anode seems to stay bright red, so it might be an internal short to grid.

When carrier is on at 100W, grid current meter goes disco, disconnecting power from driver tube returns needle back down to negative side when idling.

After quick look to datasheets, 3-400Z looks like direct replacement, but these are long gone.

3-500Z has little higher mu, but looks to be around same specs as YD-1130.

I have never been playing with these Philips tubes, so these are little weird to me.

Old Eimac datasheet has little bith higher internal capacitances than YD-1130, not much.

Physical fit seems to be perfect.