Wow, that's a first for me.
Never seen this set up before.
Make sure the friction ring slots line up, not overlapping.
Meaning the inside and outside ring slots leave a gap.
Western Gun Parts is where I got parts for my 20 including new rings.
Del Selin may have some A-5 parts.
Yes I ordered the bronze friction pieces, friction rings and the single spring today from Western Gun parts. they said they had limited stock.
Not sure Im quite following you on the gaps?