If you read Dutch, I have some reading material I could suggest.
Will give you the condensed version:
The PRCA maintain that grace is not offered, but worked by God in the heart of His people. As such they deny the offer. This position developed out of the dispute with the CRC in 1924, over the three points of Common Grace. The PRCA, in opposition to the CRC, deny common grace. The CRC marries common grace to the offer, in such a way that man can do good, and does have the power, yet being unregenerate, to accept such an offer.
Dr. Steenblok and the Reformed Congregations of N. America (and the Gereformeerde Gemeenten in Nederland), in opposition to the Netherlands Reformed Congregations (and the Gereformeerde Gemeenten (synodaal)), maintain that there is no 'unconditional welmeant offer of grace to all hearers. The condition they place is that the offer is only to the elect who have advanced to such a state that they are convinced of their own unworthiness.
So, while there are certain similarities in the views (and as such Dr. Steenblok also thought it bad terminology to use the word 'offer', there are differences of accent. The more important differences between the PRCA and the RCNA, however, in my opinion, have to deal with the Covenant view, how we handle children of believers (PRCA believe they should be treated as lambs of the flock). Both, the most important of all is the reliance by the RCNA on a mystical experientialism.
(I was born and raised as a member of the GGinN (RCNA))