Help needed, looking for an ancient rear derailleur, shimano SIS

[Trish]

Hej all!
By the chance, don't you have somewhere this rear derailleur you can miss (or don't you just know someone who can)?

(This one comes from a ~25 years old bike, for few years it has served as a trike front chain tensioner and its spring is out of order now.)

Plus points for Uppland or nearby.

Tack!

Trish

 

[LWB]

Any chance a Shimano Exage 300 (or is it 200?) could work, or is it SIS only?

 

[Trish]

Hej LWB,
I have no idea, but probably not according to pics I googled. This one has open spring area and can be rotated over 360 deg.

Actually, my trike mechanic (If I can do myself, probably I do not need ride a trike...) has been looking for another solution for two years (Well, he is a quite busy man.) with no succeess yet.