The frame lock latch and spring were in same shape across board. No 1930 available, but pix 30 & 31 of this 1914 gun should help:
http://www.gunbroker.com/Auction/Vie...Item=127896136
On yours, most likely the latch and/or the spring was replaced in the past. Both parts were unnumbered on 1930, but inter-exchangability of parts on Mauser is poor, even for unnumbered ones.