Allen has been with the Northern Football League side since 2019, having joined them from Newcastle United U18s.
He is a player who is comfortable in a number of positions and will provide plenty of versatility for the Railwaymen.
Marrs, meanwhile, has been with Sunderland RCA since 2020.
The shot-stopper’s previous clubs include Morpeth Town, Mansfield Town, Middlesbrough and Newcastle United.
He also enjoyed time playing for IFK Mora in Sweden.
Marrs will be a direct replacement for Matty Bateman, who has left the club to go in pursuit of regular game time elsewhere.
Both players go into immediate contention ahead of Saturday’s trip to Ossett United in the Pitching In NPL East Division.
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