Cannot mount an NFS file through OpenVPN

I am running Leap 42.2 on both my desktop and laptop computer. When I am running on my home network, I can mount NFS files hosted on my desktop on the laptop using my home WiFi network. I use the command (on my laptop)
mount desktop:/data/Pictures /mnt/Pictures

From the laptop programs can then access /mnt/Pictures/vacation/pretty-picture.jpg.

When I am away from home, I would like to access my files through openvpn.
From the desktop, I use
openvpn --daemon --config /etc/openvpn/server.config

I have the following as a part of server.config:
port 1194
server 192.168.33.0 255.255.255.0
proto udp
dev tun

After starting openvpn (I only want to run vpn on command, not auto startup) with ifconfig I see:
tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
inet addr:192.168.33.1 P-t-P:192.168.33.2 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:470 errors:0 dropped:0 overruns:0 frame:0
TX packets:362 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:32849 (32.0 Kb) TX bytes:200321 (195.6 Kb)

Over on my laptop, I start openvpn with
openvpn --config /etc/openvpn/remoteclient.config
(note: --daemon is not included because I have to enter the pass phrase for the certificate)

remoteclient.config contains the following info:
dev tun0
remote home 1194

If I do ifconfig, I see
tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
inet addr:192.168.33.6 P-t-P:192.168.33.5 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

Incidently, my /etc/hosts file on both machines is
192.168.1.5 desk #desktop computer local network address
25.25.25.25 home #ip address on the internet for my home (actual address hidden to protect the guilty)
192.168.33.1 vpnhost #address of my vpnserver.

The vpn connection appears to work. I can ping in both directions. I can do ssh from the laptop with any of these three commands:
ssh -p 12300 me@desk # My desktop does not do ssh on the standard port
ssh -p 12300 me@vpnhost
ssh -p 12300 me@home

Using kguard, I can see that the vpnhost command does go through the vpn and the wifi. The other two just go through the wifi (as I would expect).

As for the ports; I have my cable modem set up to port forward ports 12300 and 1194 to my desktop computer. There, I have allowed additional ports of 12300 and 1194 and modified my /etc/services file accordingly.

I would now like to mount nfs files that are on my desktop onto my laptop. If I am running locally at home, I can enter
mount desk:/data/Pictures /mnt/Pictures
and access the files in the directory just fine. But if I am away from home and using a hotel web or the library or a coffee shop, and I enter
mount home:/data/Pictures /mnt/Pictures
the mount times out.

I have tried searching for a solution, but cannot find anything that seems to match the problem I am having. Thanks for any help/

Did you try mount using vpnhost address?

I tried both
> mount home:/data/Pictures /mnt/Pictures ;Mount to my desktop at 25.25.25.25 - the isp supplied address

and
> mount vpnhost:/data/Pictures /mnt/Pictures ;Mount to the vpn host address 192.168.33.1

I believe the first one is the correct one, but I will take whatever works.

If you are going to mount using external public address, why do you need VPN in the first place? And in this case you obviously need to setup suitable port forwarding which almost prescribes NFSv4 which is using fixed port number.

Anyway, do you have firewall active on your NFS server? If yes, try first stopping it to make sure it does not interfere.
What are export options? May be server restricts allowed hosts. “showmount -e” on NFS server would show what is exported and which options.