ppp revisited

I can update my question a bit.

We have a machine, 192.168.5.88, which can go out on the net. It connects to a PPTP VPN our customer supplies (address is 204.XX.XX.XX). When it connects it gets an IP address of 10.0.1.3 as in the following:

ppp0 Link encap:Point-to-Point Protocol
inet addr:10.0.1.3 P-t-P:10.0.1.1 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1456 Metric:1 RX packets:58 errors:0 dropped:0 overruns:0 frame:0 TX packets:72 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:3

Forward is set to 1:

     sysctl net.ipv4.ip_forward
     net.ipv4.ip_forward = 1

and /etc/sysconfig/network:
NETWORKING=yes
HOSTNAME=Lemko88
FORWARD_IPV4=true

And then from doing a man on ppd it said ktune and proxyarp would make it available to other machines:

/usr/sbin/pppd call BugTussel debug logfd 1 nodetach ktune proxyarp persist linkname host

Then from my 192.168.5.191 machine I did an

    ip route add 10.0.1.3 via 192.168.5.88 dev eth0

I could ping 10.0.1.3 but not any other machines on the VPN. I even tried

    ip route add 10.0.0.66 via 10.0.1.3 dev ppp0

and independently

    ip route add 10.0.1.1 via 10.0.1.3 dev ppp0
    ip route add 10.0.0.66 via 10.0.1.1

but still could not reach 10.0.0.66 (or 10.10.0.2 or others).

Does the host machine I call have to set something too?

Tony