Used stamps exchanges.

i just received a nice lot and would like to give it the maximum satisfaction rating
but do not know how to do it. please advise.

If the rules are not respected, like if there are less then 100, you could give a negative rating.
1 or 2 is negative
3 is neutral
4 or 5 is positive

For 2 low ratings received in the last 10 exchanges, a member will be temporary suspended.

Ratings can be changed if for example the two members agree for a partial resend.

Also, it could be a good idea if you contact your partner to try to find out why there are less then 100. Maybe this was an unintentional mistake and maybe your partner would consider resending some stamps in order for you to give a higher rating.

I received stamp, but only 87, not 100 and mostly definitive. What rating I should give to this exchange?

Go to "register stamps" under exchanges on home page and just fill in the rating you want (default is 5 - max) then in the box below you can add a message if you want. Happy stamping.