Rear Hub and drum assembly too tight

[1912Minerva]

Hello All,

I thought I'd pull off my rear hub and drum assembly and check that it was ok and pack the bearing with grease. I did that but when I replaced it, I found the hub is now very tight. The wheel turned nicely before disassembly but now is almost too tight to turn by hand. I can't see what would have changed except for possibly placing the key back in another way....

Any suggestions as I am stumped????

Thanks in advance and regards,

Andrew.