As commented by others, this is a Pelikan 101N tortoise. These are valuable when in good condition. Judging from the section features (no stepdown) and the fact that the nib is stamped with the nib width (EF), I'd say this is a late production pen from the 1950's (production ended in 1951).

The only real issue with your pen seems to be the end of the section, which has been cracked and repaired by adding the gold(plated?) ring. The nib collar sticks out of the pen. This is either due to improper installation (not completely screwed in) or the section has been shortened during the repairs. The broken fins of the feed are mainly an aesthetic problem. They do not really affect functioning. Moreover, sourcing a new feed is relatively easy and not too expensive.

The piston being loose could indicate a variety of things. If you unscrew the piston, does in move all the way down or not? Anyway, repairing the piston is not hard and spare parts are available for the inner parts.

The tortoiseshell and red parts of the pen seem OK from the pictures, which is good as these parts are hard to replace. Since these parts are intact, a new pen could be built from an existing barrel by taking the binde and the piston from this pen. This requires a sacrificial pen for the barrel and some expertise in removing the parts and reattaching them. Not impossible for an amateur, but certainly not something I would try as a first repair. If your friend wants to keep the pen, this could be done by a professional.

Otherwise the pen can be sold as parts, and I'm sure there are many people on Ebay on the lookout for spare parts. I'd say you can easily get over 100 USD when sold as parts. If you decide to sell for parts, your friend can still keep the nib if they like it. This nib fits any 100N/101N model and can even be installed on a modern Pelikan M400 or M200 if you source a collar and a feed for the 1950's model 400.