German Stamps On Document, Help With Identity/Value?

Hello,
I have had this item for many years and I was wondering what this document is and if it has any value:






Thank You

One side is a delivery receipt, and the other is a customs form.

It appears to be for a parcel weighing 4 kg, shipped from Berlin, via Lübeck, to the K. Kinnari Company in Salo, Finland.

The handwriting on the receipt is a little tough, but you can see the month and year of receipt ("Elokuu 1921", or August 1921), which matches the postmark of 1 August 1921, as well as the name "K. Kinnari" and city "Salo". I can't make out the day in the date.

On the customs side, you can see the customs clearance mark "Zollamtlich geprüft".

This was an expensive package to send. I don't have my catalog of postage rates, but the rate appears to be in the ballpark. The stamps are Michel 153 (4 M) and 149aII (80 Pf). The 4 Mark stamps are from a roll. Michel CV for the stamps alone is €24. This type of item would probably sell for about €10-€30.

Thanks very much for the information I greatly appreciate it. I have been wondering about this for a long time.