Nancy...it didn't take long to get a response from a couple of members of Needlebar!
I pretty much just cut and pasted some of your comments, and didn't edit out the things that had already been answered.
Alan's remark was:
Hi All,
Pictures of this fine Pfaff Model H have been posted.
Kaiserslautern, Germany is the location of the Pfaff factory and yes, the little cup is to hold an oil can.
Huttig, Berlin will be a retailer or distributor.
Alan
James wrote:
Charlee,
I'm guessing that it's a light bracket, installed later in life. It's a fine old machine and must be somewhat of a rarity here in North America, dating from well before the days that Pfaffs were imported by distributors. The decals appear to be chrysanthemums. Well, enough speculation from me!
James
And from BJ:
Splendid machine. I have never had/used a Pfaff I could warm up to, but I could love one like that.
How long before you can wrest it from Nancy's possession? 
I'm sure there will be more comments as the day goes on, but it looks like you're right about the "doohickey"!