[ David Dewey wrote in 120522 MMDigest:

> On this model, opening the pedal door locks the keys (there's
> no way to accompany the roll!)

Mine doesn't have those control buttons you mention, sorry.  However,
one can accompany the roll!  What you need to do is make the pedal
door lever such that it can push in and out as well as left and right.

When you pull it out, it engages with the keylock lever under the keys
when opening the pedals and when you push it in, it misses that lever.
You can then decide when opening the pedal door if you want the keys
locked or not.  This has worked for me for many years without any real
modifications.

Best regards,
Bernt Damm
Sydney