I did many long rides on my 4 speed Bullet 350 and (more recent) Classic 500. The 500 possibly has similar performance to your 500 (27hp), but with the obvious advantages of a 5 speed box & modern features such as EFI and alternator electrics. Can't say I found the later disc brake to be much of an improvement on the 350s TLS drum, but I don't ride "on the brakes" anyway, preferring to try to plan ahead and modulate speed with throttle & engine braking.

Always chose more minor A and B roads for preference, only using "faster" A roads and dual carriageways where required. Typically 40-50 mph cruising, mostly in 5th over 35 mph, so minimal gearchanging. Typically 250-320 miles per day, with an early-ish start (for me that means 8 to 8.30), minimal stops (these really kill your average speeds) and aim to arrive at destination between 5 and 6 pm., so 9 to 10 hour days. Typically returning 95-105 mpg, so you can see I am not "caning" it !

Done similar on an MZ TS250/1, some times more - did from near Ardnamurchan Point to Huddersfield on one accasion (384 miles door to door) and home to home via the Ace Cafe on an ETZ251 (also around 385 miles).

Once you hare happy the bike is reliable, go for it ! A very different (more relaxing for me) experience to travelling on a faster bike when you remove the pressure on yourself of having to "keep up" with faster traffic (let the impatient pass) or feel obliged to overtake (not something either the MZ or Classic really excelled at - mainly just tractors) or push on through a series of bends.

Just chill and admire the scenery - and get there when you arrive.

Nigel B.