Tombstones

We have been in Norway for two weeks and, using the help provided on this forum, we have had significant success finding family farms in Norddal. Thanks again to Jan Peter and others for your assistance! We are in Alesund now, headed for Trondheim on the Hurtigruta this evening. (For US Dollar tourists, vacationing now in Norway is expensive, but we highly recommend it anyway.) When we personally examined the graveyards at the Norddal and Valldal churches, we noticed how few tombstones were 19th Century, or earlier. We thought we would pose this question on this expert forum: why so few earlier tombstones? It is not the age of the church (both Norddal and Valldal date from the late 18th Century). Could few farm families afford durable grave markers? Do the modern Norwegians reuse grave sites because of limited space (like in New Orleans)? Most to the point of genealogical research, is it a practice in Norway to catalog the tombstone inscriptions, graveyard by graveyard? (As you probably know already, this practice is widely practiced in North American genealogy, although the coverage is hit-and-miss and the indexing is not at all standardized in my experience.) If such comprehensive graveyard documentation exists in Norway, at least for individual graveyards, does anyone have any suggestions for tracking down Norddal and Valldal (More og Romsdal) specifically? We inspected both these churches on 16 Aug, and signs on the respective doors said that tours and open hours ceased on 15 August. That was a little frustrating, may I say. So there was no sexton or priest or other person at these churches to answer any of our questions. But I have had such helpful feedback on this forum with past questions, I thought I would add this new query. Thanks in advance for your help.